Populist attitudes and foreign policy postures: a comparative analysis of four European countries

Abstract

This article explores how populist attitudes are correlated with foreign policy postures at the public level in four European countries: France, Germany, Great Britain, and Italy. We provide first evidence adjudicating between two rivalling perspectives. One perspective focuses on the ideational core of populism and argues that it entails substantive beliefs and values that may inform foreign policy preferences – just like any other ideology. Another perspective focuses on the thin-centredness of populism and argues that no policy implications can be derived from populist ideas. Analysing original survey data, we find strong and consistent associations of populist attitudes with two foreign policy postures, militant internationalism and isolationism, and weaker and less systematic associations with two others, cooperative internationalism and global justice orientations. Importantly, these patterns are independent of host ideologies. We discuss the implications of these findings for the question of how “thick” populism is and what that may mean for the politics of (European) foreign policies in times of a continuing populist Zeitgeist.

Introduction

Extensive research has tackled both supply and demand side aspects of the rise of populism (Mudde and Kaltwasser, 2018; Mols and Jetten, 2020; Guriev and Papaioannou, 2022; Guiso et al., 2019). One of the few aspects that has received comparatively little attention is the nexus of populism and classical foreign policy, relating to conflict and cooperation between nations (for exceptions see Heinrich et al., 2021; Destradi et al., 2021; Pevehouse, 2020; Verbeek and Zaslove, 2015; 2017; Wehner and Thies, 2021). This is hardly surprising, since populist elites have neither placed this policy area at the centre of their courting of votes, nor has it been of particular importance to voters. It is, therefore, safe to argue that foreign policy has played, at best, a subordinate role in the rise of populism. Today, however, populists are established political players in many countries. Through their entry into governments and national parliaments, they have gained considerable influence in all policy areas, including foreign policy issues. In addition, foreign policy is much more salient than it was a few years ago due to Russia’s invasion of Ukraine and is likely to remain so for the foreseeable future – at least in Europe. Under these altered contextual conditions, it is highly relevant to address the relationship between populism and foreign policy.

In this article, we contribute to closing this research gap by examining the populist “demand side,” on which no analyses have been conducted to date (but see Rathbun, 2013). The core question is whether populist citizens have distinct preferences about the basic principles that should guide their country’s foreign policy. Focusing on such postures (Hurwitz and Peffley, 1987: 1104) is a natural starting point, as they are the cornerstone of mass belief systems on foreign policy – they are relatively stable and guide citizens’ evaluations of more specific policy issues (Hurwitz and Peffley, 1987; Wittkopf, 1990; Irondelle et al., 2015; Gravelle et al., 2017; Mader and Schoen, 2023). Moreover, it has been argued that these postures are ideologically structured. For example, citizens on the political right tend to be more willing to support the use of military force and are more sceptical of multilateralism conducted through international organizations, while those on the left tend to hold opposite views (Eichenberg 1989; Wittkopf, 1990; Nincic and Ramos, 2010; Rattinger et al., 2016). So, what about citizens sympathizing with the populist creed? What foreign policy principles do they subscribe to?

This question takes up a central issue in populism research, namely whether populism is too “thin” at the ideational level to put forward a comprehensive and coherent programme for solving crucial political questions. To provide such a programme, some argue that populism is “reliant on or piggybacks onto other more substantive political ideologies” (Schroeder, 2020b: 14). Others dispute this claim (Schroeder, 2020a; Neuner and Wratil, 2022). Research that deals with populism and foreign policy on the supply side mirrors this state of debate. There are researchers who argue that, despite some similarities across populist parties and leaders, there is not one populist foreign policy, but several (e.g., Destradi et al., 2021; Verbeek and Zaslove, 2017; Wehner and Thies, 2021). Accordingly, host ideologies may be the more relevant ideational guide in the foreign policy arena than the thin-centred ideology of populism. Other scholars, however, have engaged with the constitutive elements of the populist ideology and theorized their implications for foreign policy (e.g., Heinrich et al., 2021; Pevehouse, 2020; Verbeek and Zaslove, 2017). Analogous to this debate on the supply side, we examine on the demand side whether populist attitudes have unique variance with basic foreign policy postures. In short, we aim to find out whether citizens with populist views favour particular foreign policy principles, irrespective of their “thicker” ideological stances.

To do so we analyse original survey data collected in France, Germany, Great Britain, and Italy in 2019 (N = 7,788). The results show that populism is consistently and substantively associated with certain foreign policy postures. Across countries and ideological camps, populists in all four countries are more militant in their internationalism and more isolationist than citizens who do not subscribe to populist ideas. Populists are thus less eager to get involved in international affairs but tend to have a positive attitude towards the military and using force as an instrument of foreign policy. We discuss the implications of these findings for domestic and European politics in times of increased salience of foreign and security issues.

Theoretical framework

Populism and foreign policy: charting the terrain

During the last few years, interest in populist foreign policy has increased (for reviews see Destradi et al., 2021; Löfflmann, 2022; Chryssogelos, 2021; Verbeek and Zaslove, 2017). Most of the attention, however, has been devoted to the policies and politics of populist elite actors (Cadier, 2024; Kesgin, 2020; Mead, 2002, 2011; Wehner, 2023). This research has found that while it is possible to identify common general foreign policy themes among certain populist actors (such as anti-globalism or anti-Americanism), the effects of populism on foreign policy as a whole are quite diverse (Taş, 2022: 564). While populist parties and governments all “cast their positions in terms of the pure people versus the corrupt elite” (Verbeek and Zaslove, 2017: 386), they support a wide array of foreign policies, depending on the thick-ideology populism attaches itself to, on the interests and the personality of leaders (Thiers and Wehner, 2022), and the roles these actors aim at playing in the international arena (Destradi and Plagesmann, 2019). For example, in comparing Brazil’s Bolsonaro and Mexico’s Lopez Obrador, Wajner and Wehner (2023) have shown that although populist leaders typically veer isolationist in order to substantiate their anti-elitist and anti-globalization agenda, at times they embrace internationalism by pointing to transnational solidarities between peoples. Incorporating various dimensions of internationalism into existing populist rationale depends on whether a particular position brings the leader an advantage in terms of legitimacy, political support or differentiation from previous leadership (Wajner and Wehner, 2023: 10). Consequently, engagement with the international arena is often driven by domestic political calculus, not based on populist ideology per se.

Other scholars also stress the diversity of populist foreign policy but zero in on the fact that populism is usually combined with other traditional (thick) ideologies. Accordingly, the latter serve as host ideologies by specifying the opposition between “the people” and “the elite” that is at the heart of populist ideology (Giurlando, 2021): right-wing populist parties and movements use a nativist definition of the people, who are seen as struggling against cosmopolitan elites. Left-wing populists see disadvantaged socioeconomic groups suppressed by the rich, capitalist elite. Other blends of populism define the “pure” people as historically belonging to a smaller territorial unit who oppose territorial integration into larger entities (e.g., Verbeek and Zaslove, 2017: 392). Against this backdrop, some scholars have concluded that there is no single populist foreign policy; rather, populist foreign policy varies with the host ideology (e.g., Verbeek and Zaslove, 2017; Destradi et al., 2021). ¹

So, while many studies have focussed on the elite level and show diversity rather than uniformity of populist foreign policy, we know almost nothing about populists at the population level (but see Rathbun, 2013). Do populist citizens also show diversity in opinion or do they have common views on basic foreign policy principles that are distinct from non-populists? In other words, are there general foreign policy preferences among populist citizens, irrespective of context or (thick) ideology? The following theoretical analysis first clarifies our conceptual approach to populism at the population level. Then we discuss reasons why there might be (no) connections between populism and foreign policy preferences.

We rely on the so-called ideational approach to the study of populism (Mudde, 2017; Hawkins et al., 2018). Accordingly, populism is defined as a thin ideology that “considers society to be ultimately separated into two homogeneous and antagonistic groups, ‘the pure people’ versus ‘the corrupt elite’, and which argues that politics should be an expression of the volonté générale […] of the people” (Mudde, 2004: 543). In other words, populism consists of a set of ideas that can be found at different levels, including the citizen level. Populism at the individual level is generally referred to as populist attitudes (e.g., Akkerman et al., 2014; Castanho Silva et al., 2018; Erisen et al., 2021; Hawkins et al., 2012; Schulz et al., 2018). Together, these ideas form an attitudinal syndrome linked through a non-compensatory mechanism (Wuttke et al., 2020). As such, populism lies at the intersection of several dimensions such as anti-elitism, support for popular sovereignty, and Manicheanism (e.g., Akkerman et al., 2014: 1326; Castanho Silva et al., 2018; Elchardus and Spruyt, 2016; Spruyt et al., 2016).

Building on this conceptualization, at the core of populist ideas lies the strict binary distinction between citizens and elites. This highlights two integral components that deserve attention when it comes to establishing links between the public’s populist attitudes and their views on foreign policy.

First, attitudes towards the role of elites and their (adversarial) relationship to citizens are of key importance in populist ethos; it involves opposition to the delegation of power to elites and mistrust of positions held by elites and elite-controlled organizations (e.g., Pevehouse, 2020). In the foreign policy domain, international organizations are a prime example. Populist leaders usually portray them as lacking clear accountability structures and as following their own agenda that is detached from the public interest (Bearce and Jolliff Scott, 2019; Zürn, 2022). Since, according to populists, the people are the primary source of legitimacy, people-centrism often justifies and even calls for anti-elitism.

Defining the elite against whom populists fight is, essentially, a matter of context: while Donald Trump attacked the Washington establishment, European populist parties often discredit the EU’s bureaucracy (Destradi and Plagemann, 2019: 713–714; see also Chryssogelos, 2021 on European parties and Euroscepticism). Likewise, populists promise a voice for the underrepresented and a come-back for the paradigm of national interest/anti-globalization. Consequently, the enemies needed for staging the fight can differ from case to case (Jakupec, 2018).

Second, a Manichean worldview implies that populists perceive the world in a strictly dichotomous way that distinguishes between good and evil, which may give rise to moralistic thinking (e.g., Hawkins et al., 2018). This rather simplistic, black-and-white view of the world seems akin to a strong need for cognitive closure (Kruglanski and Webster, 1996), which expresses individuals’ desire for clear answers – even if they are wrong – and an aversion towards ambiguity. Following this line of reasoning, high scorers on populist attitudes should prefer simple distinctions and decision rules, whereas low scorers should be more open to complexity and compromise.

When considering the possible connection between populist attitudes and foreign policy attitudes, we focus on foreign policy postures, that is, attitudes towards general principles to which the foreign policy of the individual’s country could conform (Hurwitz and Peffley, 1987: 1104). They provide benchmarks for evaluating specific policies and therefore bring coherence, consistency (Hurwitz and Peffley, 1987; Kertzer et al., 2014; Rathbun et al., 2016) and – because they are relatively context-independent (e.g., Mader and Schoen, 2023) – stability to citizens’ attitudes. According to Gravelle et al. (2017), four dimensions underlie citizens’ beliefs vis-à-vis foreign policy in the Western hemisphere. Isolationism refers to the question whether international involvement should be sought at all. Second, militant internationalism revolves around projecting military power abroad. Third, cooperative internationalism covers features such as working through international organizations and cooperation. Finally, global justice refers to the redistribution of wealth across borders (Gravelle et al., 2017). When considering potential links between populist attitudes and foreign policy attitudes, we rely on these four dimensions.

Theorizing the role of populist attitudes for foreign policy postures

Links between citizens’ populist attitudes and foreign policy postures may result from multiple mechanisms. According to one line of reasoning, people could reflect on policy themselves by evaluating them in terms of whether or not they are compatible with general principles that are important to them (e.g., Hurwitz and Peffley, 1987; Peffley and Hurwitz, 1985). From this perspective, populism might represent such principles against which to judge foreign policies, just like others have argued that (thick) ideologies (Hurwitz and Peffley, 1987; Nincic and Ramos, 2010), value priorities (Goren et al., 2016; Rathbun et al., 2016) or moral principles (Kertzer et al., 2014) serve such a function. Going back even further in the funnel of causality, research suggesting that personality influences foreign policy preferences also implicitly assumes some type of natural-affinity mechanism based on abstraction and reasoning (Schoen, 2007; Wajner and Wehner, 2023). ²

Such cognitive processes may imply some level of conceptual sophistication, as applying general principles to specific policy problems can be cognitively challenging (Goren, 2001). This requirement is mitigated, however, when considering another possible mechanism linking populist attitudes and foreign policy postures. Accordingly, citizens often rely on cues from trusted, more sophisticated sources to do the conceptual heavy lifting for them (e.g., Zaller, 1992; Kertzer and Zeitzoff, 2017). By receiving such cues over extended periods of time, citizens may learn “what goes with what” (Converse, 1964: 212) and how to link populist ideas and foreign policy postures – or at least appear to do so. ³

In sum, prior research on foreign policy attitudes suggests that we may expect links between populist attitudes and foreign policy principles where ideational affinities between populist principles and foreign policy positions exist and repeated elite cueing is likely to have established a quasi-logical connection of “what goes with what.” We hence proceed to discuss such potential links between populism and each of the four foreign policy principles in order to arrive at expectations about the possible effects of the former on the latter at the population level, irrespective of political context and host ideology. In a second step, we turn to the more complex notion that host ideologies must be accounted for when thinking about links between populism and foreign policy.

Involvement in international affairs, which for a long time were considered a domaine réservé, implies delegation of authority to elites and potentially the need for compromise in the international arena. Thus, the will of the people can hardly serve as the sole guide for policy-making; rather, elites have some leeway in making decisions, and these decisions may deviate from the “popular will.” Such deviations may be instrumentalized by populist actors in order to cultivate electorally profitable anti-elitist sentiment among the public. Consequently, populist leaders may embrace and promote isolationism as a measure of “protecting” the people from either (foreign) ideas, enemies or alleged economic hardship (Wajner and Wehner, 2023). Hence, we anticipate that high scores on populist attitudes go hand-in-hand with increased support for isolationism.

Turning to cooperative internationalism, we may expect populist citizens to be sceptical of it as well. International organizations and negotiations usually mean that elites play a significant role and make decisions that may not be in line with the popular will. In a similar vein, elite cooperation at the international level usually leads to compromise, which populists dislike. Cooperative internationalism may also imply high costs, economic and beyond, and populist leaders may communicate these costs to the people, thus leading to less support. In sum, populists’ lack of support for cooperative internationalism may be anchored both in an anti-elitist stance and also a “people’s first” attitude. Accordingly, high levels of populist attitudes may be expected to be linked to opposition to cooperative internationalism.

For sharing wealth across borders, a similar reasoning yields the expectation that high scores on populist attitudes might correlate with a rejection of global justice. In particular, the provision of foreign aid implies a long chain of delegation from the people to the elites, often involving international organizations. Hence, populists may reject such policies due to their anti-elite stance (Heinrich et al., 2021). Furthermore, concern for the well-being of others in far-removed corners of the world may be used in populist rhetoric to imply disregarding the interests of the people at home (Bayram and Thomson, 2022; Suzuki, 2023).

Finally, militarist internationalism revolves around the projection of military power abroad. To be sure, the military is a hierarchical organization in which elites play a huge role. At the same time, the use of force may be considered a simple method of conflict resolution that helps avoid complicated and complex bargaining at the elite level. Consequently, support for militarist internationalism may resonate well with populists’ elite scepticism and taste for clear-cut distinctions and decisions; support for populist ideas may thus go hand-in-hand with support for projecting military power abroad. As shown by Rathbun (2013: 30) when discussing the role Jacksonian tendencies play in explaining militant internationalism among Tea Party voters, isolationist tendencies can go hand-in-hand with militant internationalism, with the association rooted in the military and not the internationalist aspect of militant internationalism. The importance of the military for isolationists is in line with the high value placed on national sovereignty, typical of populism in Europe and elsewhere.

Thus far our theoretical analysis has ignored that populism is often combined with other traditional (thick) ideologies. Do we have to account for this fact if we want to understand the link between populism and foreign policy? Which implications does this blending of populism and host ideologies have for how citizens think about foreign policy? Theoretically, there are two possibilities. First, both populism and host ideology might provide different considerations about foreign policy, which in turn shape citizens’ postures independently and additively. This is what we have implicitly assumed above, when we derived expectations about the link between populism and postures without regard to host ideologies. In this scenario, host ideologies are only relevant as potential confounders of the association between our quantities of interest. ⁴ To understand the link between populism and postures, we would merely have to account for them in the statistical analysis and should expect the association between populism and foreign policy postures to be the same among citizens on the left and the right.

The second possibility is that populism and host ideology interact in shaping foreign policy postures, that is, that one set of ideas dampens or amplifies the effects of the other. Operationally, this would mean that the associations between populism and foreign policy postures differ between left-wing and right-wing citizens or, viewing the interaction “from the other side,” that the associations between host ideology and foreign policy postures differ between populists and non-populists. Several mechanisms might create such interactions. Building on the idea that populism makes people less likely to accept compromises, for example, we might expect that left- and right-wing populists differ more strongly in their foreign policy postures than left- and right-wing non-populists. However, our goal here is not to speculate on potential mechanisms or forward specific hypotheses on interactions. We take a more exploratory route and merely perform the diagnostic task of documenting whether or not there is empirical evidence of such interactions.

Research design

Data and national cases

To test our hypotheses, we draw on data from online surveys conducted in France, Germany, Italy, and the United Kingdom (henceforth UK) in the summer of 2019. In total, we surveyed 7,788 respondents (FRA: 1,866; DEU: 1,899; UK: 1,976; ITA: 2,047). The French, German, and British surveys were fielded by YouGov in August 2019 using nation-specific online open-access panels. Respondents were recruited based on quotas on gender, age, and education. In Italy, the survey was fielded by GfK in June–July 2019. The sample was selected from a probability panel held and managed by the same company. As the countries in our sample differ considerably in their political systems, strategic cultures, and political cultures, we analyse them separately.

The four countries were selected for two reasons. First, they are the most powerful European countries and hence of substantive importance. This importance is increased by the fact that in all four countries, populist parties have had significant electoral success and, consequently, gained political influence. It is hence important to understand the foreign policy preferences of the populists, including those at the citizen level. Second, there are important differences between the four countries – both in terms of their foreign policy cultures and populist movements. At the moment of fielding the survey, in Germany and France, for example, populists were in parliament but not in government, while in Italy and, arguably, the UK, they had executive power. In the summer of 2019, the UK was in the middle of a succession of Conservative-dominated/influenced governments, with many debates revolving around the 2016 Brexit Referendum and its implementation in 2020 (Hobolt, 2016). While a natural association between populism and conservatism seems somewhat improbable (not in the least because of the former’s critical stance against elites, and the latter’s support of elites), in the context of post-Brexit debates on deciding how and when to leave the EU, populism gained traction in the UK. As Alexandre-Collier (2022) points out, the Conservative Party included either procedural or substantive populist elements, around the time of Brexit and afterwards, especially in terms of Johnson’s anti-immigration discourse, and hard stance on Brexit. It is beyond the scope of this article to provide analyses of the boundary conditions of each case. However, the contextual diversity does allow us to diagnose whether there is variation in the associations between populist attitudes and foreign policy postures in different contexts. Finding consistent patterns of associations across contexts would strengthen – but not conclusively prove – the view that there may be one distinct populist foreign policy after all. ⁵

Measures

Foreign policy attitudes were operationalized using the conceptualization suggested in Gravelle et al. (2017). These authors suggest a four-dimensional configuration of foreign policy beliefs in which the three traditional dimensions found in the US, namely internationalism, militant and cooperative, and isolationism, have to be integrated with a fourth one tapping public support for redistributive and humanitarian policies, such as foreign aid. According to this line of thinking, the best way of describing the belief structure of the European public is made on the basis of four main postures, called militant internationalism, cooperative internationalism, isolationism, and global justice.

To build our four measures of the foreign policy postures we relied upon items suggested by Gravelle et al. (2017; 2020). Militant internationalism was operationalized using two items, one related to the role of the military and another to support for the use of force in international relations. Cooperative internationalism was measured by three items on whether the respondent’s country should work more through international organizations (e.g., the UN), whether the main goal of a world leader is to build international consensus or to be committed to diplomacy. We assess the isolationist dimension with three items stressing the importance of focusing on the need to stay aloof from international relations. The last dimension elicits attitudes towards global justice by means of three items asking whether the respondent’s country should share its wealth with other nations, spend significantly more on foreign aid, or whether, instead, the country really does enough to help the world‘s poor. Cross-country dimensionality was tested using aggregate and country-specific exploratory factor analysis and simple additive indexes for these four dimensions were computed and rescaled to range from 0 to 1. ⁶

Moving now to the independent variables, we rely on an assorted set of items of which some were adapted from survey studies of populism in other contexts (Akkerman et al., 2014; Oliver and Rahn, 2016), while the most were of our own construction. These items mostly cover anti-expert elites’ attitudes, with two items gauging whether experts do not know much or respondents are more confident in their own opinion than other people’s facts, and a Manichean outlook when it comes to conceiving politics, via three items eliciting whether political opponents have evil intentions, whether politics is a struggle between good and evil or conceived as a conflict between “us versus them.” After testing the internal structure of the responses to these items via exploratory factor analysis, we created two subdimensions and combined them building on the idea that populism is a non-compensatory concept and the so-called “Goertz approach” (Wuttke et al., 2020). In this view, populism is seen as a non-compensatory multidimensional concept in which each component constitutes a necessary condition for the presence of the phenomenon. Thus, “populists” are respondents who score high in all the subdimensions. Following this approach, we use a standard operationalization strategy and create the final scores using the minimum value of the concept subdimensions. Eventually, all the scores were standardized on a 0 to 1 scale, with the mean 0 and a standard deviation of 1. ⁷

We also explored how our scale performs in comparison with other two popular batteries measuring populist attitudes – the Akkerman et al. (2014) and Castanho Silva et al. (2018) scales – using the case of Italy where all three measures were administered to the sample. Results showed them to be consistent. ⁸ To be sure, we do not claim that our measure does not come without any problems. It has, however, face validity as it captures the relevant subdimensions using an established technique and appears to perform as well as other widely used measures.

Our second main independent variable is the ideological stance on the Left-Right continuum. ⁹ Ideology is particularly relevant here because the ideological interpretation of populism suggests that populism is a “thin ideology” and the most obvious thick ideology to whom it may attach itself is represented by the left-right continuum. We measured respondents’ position by asking them to place themselves on a left-to-right continuum, with the response scale ranging from 1 (left) to 7 (right). To allow for non-linear effects, we coded respondents into six groups, one for each ideological orientation (left, centre-left, centre, centre-right, right) plus a category for those who refused to answer this question or expressly said they did not recognize themselves in this scale. Finally, we control for several sociodemographic variables, including a dummy for female respondents, age measured in years, and education measured via a categorical variable (“low-level education” being the reference category, “medium-level education,” and “high-level education”).

Statistical models

We test our hypotheses running a set of country-specific linear regression models summarized by the following general notation:

$${y_i} = \beta {X_i} + \alpha + {\varepsilon _i}$$

$${\varepsilon _i} \sim N\left( {0,{\sigma _\varepsilon }} \right)$$

where ${y_i}$ is the foreign policy posture (either militant internationalism, cooperative internationalism, isolationism or global justice posture) of respondent $i$ , ${X_i}$ is a matrix of explanatory variables with their respective coefficients $\beta $ , $\alpha $ is the country intercept, and ${\varepsilon _i}$ is the residual error term. In terms of independent variables, we include populism and left-right ideology as the main variables of interest and standard socio-demographic controls, namely age, gender and education.

In describing the results, we first assess the direct impact of populism on our four policy attitudes while controlling for host ideology. We then consider the role of host ideologies on foreign policy attitudes as dependent on populist attitudes via interaction terms. Country-specific models help us disentangle any potential heterogeneity in the considered effects at the country-level across France, Germany, Italy, and the UK. It is worth noting that our analysis cannot avoid the potential circularity of studying attitude-to-attitude relationships, so in the subsequent discussion we do not intend to imply a specific causal ordering among the considered variables as this is difficult to identify with certainty. When we use the term “effect,” this is meant in the sense of a statistical association, rather than denoting a causal effect.

Results

We begin with descriptive statistics on the key measures. Table 1 shows that sizeable minorities – roughly one in three – score above the mid-point of the populism measure in all countries, indicating a large potential for populist ideas. ¹⁰ As for the foreign policy postures, the distributions correspond with prior findings (Gravelle et al., 2017). While the publics of all countries are generally supportive of cooperative internationalism, there are differences with respect to the other three postures. As one might expect, given the different foreign policy traditions, French and Brits are supportive of an assertive foreign policy that projects power abroad; Italians and Germans are more hesitant when it comes to militant internationalism. With respect to the remaining postures, we find a rift between the UK and continental Europe. Brits score lower on isolationism than Germans, Italians, and French. ¹¹ Furthermore, support for sharing prosperity with other countries is higher in continental Europe than in the UK, although it is moderate overall in absolute terms. In France, where support is highest, only around a third of respondents score above the mid-point on the global justice scale.

Table 1 Descriptive statistics of key measures

Note: Top half shows index means with standard errors in parentheses. Bottom half shows percentages of respondents with index scores above the mid-point of the scale.

Turning to the results of the regression analysis, the direct effect of populist attitudes on foreign policy postures is shown in Tables 2–5 for militant internationalism, cooperative internationalism, isolationism and global justice, respectively. The effect of populist attitudes is relevant across the four foreign policy postures and its effect is consistent in sign across the four considered countries with some minor exceptions. Specifically, populist attitudes are positively associated with militant internationalism; respondents showing higher levels of populism also tend to be more militant internationalists in all the four countries. When it comes to cooperative internationalism, associations are more unstable and seem tied to the country context. In fact, the association between populist attitudes and cooperative internationalism is negative and statistically significant in Germany and the UK, it turns positive and significant in France, while it is null in the case of Italy. While we are unable to offer a clear-cut answer, we can advance a few arguments related to a potential French exception.

Table 2 OLS model of militant internationalism posture on populism and other predictors

Note: Reference category for left-right self-categorization is “centre”. Standard errors are in parenthesis. * p < 0.05, ** p < 0.01, *** p < 0.001. Control variables are not shown.

Table 3 OLS model of cooperative internationalism posture on populism and other predictors

Note: Reference category for left-right self-categorization is “centre”. Standard errors are in parenthesis. * p < 0.05, ** p < 0.01, *** p < 0.001. Control variables are not shown.

Table 4 OLS model of isolationism posture on populism and other predictors

Note: Reference category for left-right self-categorization is “centre”. Standard errors are in parenthesis. * p < 0.05, ** p < 0.01, *** p < 0.001. Control variables are not shown.

Table 5 OLS model of global justice posture on populism and other predictors

Note: Reference category for left-right self-categorization is “centre”. Standard errors are in parenthesis. * p < 0.05, ** p < 0.01, *** p < 0.001. Control variables are not shown.

First, historically, France has been an important actor on the international stage, and its engagement with/presence in various parts of the world (especially Africa) testifies for its ambitious global agenda. Given that the items making up the cooperative internationalist dimension measure support for multilateralism and diplomacy (as opposed to military means), it is possible that the positive correlation between populism and cooperative internationalism can be related to this global power agenda that France may subscribe to. Second, during recent years, the (populist radical right) Front National has been moderating its foreign policy stance, transitioning from stark opposition to international organization to reforming them from within. An instrumental view of international organizations – that is, they can be a vehicle for advancing France’s national interest – would also help understand the positive correlation between populism and cooperative internationalism. Moreover, it is also possible that the populist elites adjusted their anti-EU positions in order to better respond to the public’s decreasing appetite for leaving the EU (according to ESS data, between 2016–2017 and 2020–2022, support for leaving the EU has decreased in many EU countries, with France among them) (Henley, 2023).

Proceeding with our assessment, estimates are again consistent when considering the relationship between populist attitudes and isolationism. Here, stronger populist orientations are associated with a tendency for isolationist views in foreign policy affairs regardless of the national context. Conversely, populist attitudes show a negative association with the global justice posture in the four countries under examination.

Crucially, the effects of populist attitudes hold when controlling for the left-right ideological preferences. Taking into account ideology is key in assessing the association of populist attitudes with foreign policy postures, especially as we conceive populism following an ideational approach. Tables 2–5 show that centre-left and left-wing respondents tend to be less represented among militant internationalists, while people positioning themselves on the centre-right (mainly in Germany and UK) and right tend to show stronger attitudes towards the use of military abroad (the reference category on the regressions is the “centre” category). In contrast, we can observe that respondents placing themselves on the left side of the ideological spectrum are more inclined to share attitudes towards non-military engagement and support for international institutions and cooperation (with France being an exception) while citizens placing themselves on the right side are significantly less prone to it. At the methodological level it is noteworthy that in the case of France, the effect of ideological positioning on the left is still positively correlated with support for cooperative internationalism, just like in the other countries, but lacking statistical significance.

Ideology also matters for isolationism postures, as centre-left (except in France and UK) and left-wing respondents are less likely to be isolationists, while centre-right and right-wing respondents (except in UK) are more inclined to avoid involvement with other countries, refuse to risk one’s citizens’ well-being through international entanglements and focus on one’s own business. Global justice postures, that is, showing global egalitarian aspirations, decreases as respondents position themselves increasingly on the right, a tendency that applies to all four countries. Last, our data allow us to test whether those who are unable to place themselves on the left-right scale have yet a different foreign policy outlook, as this was an explicit option in the French and Italian surveys. As such, people who do not position themselves on the ideology scale are less likely to be cooperative internationalists (in France) and less in favour of global justice, while they score higher in terms of isolationism than people situated on the centre position (in both countries).

To sum up, the association of populist attitudes and foreign policy postures is still relevant when including ideology into the regression models. In brief, people high on populist attitudes seem to be more prone to militant internationalism and isolationism and less likely to hold a global justice posture in foreign affairs. ¹²

The final question to be addressed is whether there is evidence of interactions between host ideologies and populist attitudes. In the previous analysis, we examined whether populism provides citizens with reasons to adopt certain foreign policy stances that go beyond what the host ideologies offer. Now we turn to the possibility that one set of ideas dampens or amplifies the effects of the other. Statistically, we do this by including corresponding multiplicative terms (populist attitudes * left-right self-placement) as independent variables in the regressions. All other specifications remain the same. Since the regression tables from such models are difficult to interpret, we display graphical results showing post-estimations. Moreover, for the sake of simplicity, we do this merely for the opposing ideological poles, namely the left-wing and right-wing citizens. Full regression tables can be found in the online Appendix, including F tests for the change in R² between nested – interaction and non-interaction – models (Tables A8–A11).

Figures 1 to 4 plot the predicted postures at different levels of the populism scale, conditional on citizens placing themselves on the left (in black) and the right (in grey) of the general ideological spectrum. If there are interaction effects, these are shown in this form of representation by different slopes, while equal slopes mean that there is no interaction. Differences between citizens on the left and the right, for any given level of populism, are indicated by the distance between the slopes.

Figure 1. OLS model of the effect of populism conditional on ideology for militant internationalism posture.

Note: Postestimations made for categories “Left” and “Right” of the left-right self-categorization variable. Bars show 95% confidence intervals.

Figure 2. OLS model of the effect of populism conditional on ideology for cooperative internationalism posture.

Note: Postestimations made for categories “Left” and “Right” of the left-right self-categorization variable. Bars show 95% confidence intervals.

Figure 3. OLS model of the effect of populism conditional on ideology for isolationism posture.

Note: Postestimations made for categories “Left” and “Right” of the left-right self-categorization variable. Bars show 95% confidence intervals.

Figure 4. OLS model of the effect of populism conditional on ideology for global justice posture.

Note: Postestimations made for categories “Left” and “Right” of the left-right self-categorization variable. Bars show 95% confidence intervals.

The most important finding from a bird’s eye view is that there is little evidence of systematic interactions. Although there are individual cases of interaction – described in more detail immediately below – mostly we find that the association between populist attitudes and foreign policy postures is the same among left-wing and right-wing citizens (that is, parallel slopes).

A closer look shows that in all countries, the correlation between populism and militant internationalism is the same in both ideological groups. Militant internationalism scores rise in parallel with populism scores among left-wing and right-wing respondents, although they are generally higher among right-wing respondents. We also find no interaction between populist attitudes and ideology when we look at cooperative internationalism in three out of four countries. Surprisingly, in Germany, right-wing respondents tend to be prone to hold this posture when populist attitudes increase. We are unable to make sense of this finding, and suspect it to be some kind of methodological artefact. Turning our attention to isolationism, again we confirm that respondents with high populism show higher aversion towards involvement beyond national borders and this is so across the two sides of the ideological barricades. Contrastingly, stronger populist attitudes are linked to lower scores on the global justice dimension regardless of the ideological positioning of respondents (with the exception of leftists in France). These patterns deserve replication and closer examination in future research. For the time being, our exploratory analysis suggests that the association between populism and foreign policy postures does not vary significantly between (these) host ideologies.

Conclusion

A recurring theme in research on populism and foreign policy is that there is not one populist foreign policy, but several (e.g., Destradi et al., 2021; Verbeek and Zaslove, 2017, Wehner and Thies, 2021). Accordingly, due to the alleged thin-centred nature of populism, any effects it might have on foreign policy can only be understood by taking into account the “host ideology” it attaches itself to. In this article, in contrast, we find associations between populist attitudes and foreign policy postures at the public level that are independent of host ideologies. Moreover, these associations are consistent across four European countries.

Populists in France, Germany, Italy, and the UK score higher on militant internationalism and isolationism but lower on global justice than their compatriots who do not subscribe to populist ideas. Importantly, these associations are robust to different ways of accounting for host ideology – they persist no matter whether we account for left-right self-placement as another independent predictor or as a moderator. Undoubtedly, our consideration of host ideologies using left-right self-placement is minimalist and invites further analysis. The fact that the results replicate when we use nativism as an alternative interaction variable (see Appendix) increases our confidence in the robustness of our findings. As for country differences, only in the case of cooperative internationalism do we find differences, although these effects are not easier to interpret when host ideologies are taken into account. As such, cooperative internationalism is an important special case that warrants further investigation. However, it hardly detracts from the central conclusion of the present analysis, namely that populists seem to exhibit distinct systems of foreign policy attitudes.

These findings have important implications for the study of both populism and foreign policy. In populism studies, the notion that populism is “thin-centred” is based on the observation that there are different varieties of populism that define in different ways who are the “bad elites” and who count among the “good people.” Hence, these specifications themselves – that have tremendously important implications for policy preferences – are not elements of populism, conceived of as a unique bundle of ideas. Our findings suggest that this thin-centred populism may be “thick enough” to have distinct, independent effects on populists’ thinking about foreign policy. To recap in exemplary form what we discussed above: Manicheism and a general distrust of expert elites – ideas which constitute (thin-centred) populism – have certain logical affinities to basic principles in foreign policy. For example, foreign policy is conducted by elites, and hence the more active a country is in international affairs, the more power elites have to shape the lives of ordinary citizens. Accordingly, isolationism seems to follow from the populist core element of anti-expert elitism. Similarly, a Manichean attitude could make it easier to accept a black and white interpretation of international affairs, making populists more prone to the use of (lethal) military force because those on the receiving end are considered as evil and hence more easily dehumanized, which is an important way of removing moral qualms about killing. Against this backdrop, the label of “thin-centredness” seems like a misnomer when speaking of populism at the citizen level.

The implications for foreign policy research is that populist foreign policy might encounter potential rejection by the public when it runs counter to the patterns reported here. It is, however, too early to draw such a conclusion with certainty, as several assumptions that we are in no position to evaluate would have to hold. It presupposes, for example, that the patterns we have found endure even when populist leaders try to convince their followers of their preferred policy positions. ¹³ Future research should explore this issue, for example by testing the malleability of foreign policy attitudes of the populist public in the face of populist elite messaging.

More general caveats relate to the generalizability of these findings to other countries beyond Western Europe. Clearly, more comparative research is needed to address this issue. Furthermore, our results may not generalize even for the countries analysed. In the time period of data collection, foreign policy was not particularly salient, and hence elite messages that could lead to country-specific patterns via the cueing mechanism were scarce. The more salient foreign policy is, the more potential there is for country-specific dynamics – including elite position shifts that might lead to additional complexities (cf. footnote 3). Furthermore, as noted above, we have assumed rather than tested a certain direction of causality – namely, that citizens form general foreign policy preferences on the basis of populist convictions. The correlational evidence we have shown can be reconciled with this causal story but does not prove that it is true. Research designs that overcome this limitation should be applied in order to draw robust conclusions about this question.