This article examines the abiding “one China” contention between the People's Republic of China (PRC) and the Republic of China (ROC or Taiwan), focusing on their 2008–2016 cooperation and the ensuing political stalemate. It does so by investigating the PRC's and the ROC's respective legal frameworks and the positions of the major political actors, including the Chinese Communist Party and both Taiwan's Kuomintang and its Democratic Progressive Party. While the PRC maintains its “one-China principle,” and the ROC's legal system retains some “one China” elements, the idea of “one China” has been in flux in Taiwan. The traditional conceptualization of “one China” has been increasingly challenged in Taiwan's democratic era by the rise of a countervailing Taiwanese national identity and opposition to the PRC's insistent agenda to absorb the island. These dynamics are rapidly minimizing the appeal and political utility of any “one China” notions in China–Taiwan relations.

Fifty years after the current “one China” framework emerged in international politics, the cross-Taiwan Strait “one China” dispute has transformed from its historical nature of indivisible sovereignty. As Taipei has stopped competing internationally to represent “China” since 1991, Beijing now worries that compromising its “one-China principle” in cross-Strait reconciliation would enhance Taiwan's separate statehood internationally and enable the island to push towards de jure independence. In contrast, Taipei worries that any perceived concessions on the question of “one China” would enhance China's sovereignty claim over Taiwan and enable Beijing to push for unification coercively with fewer concerns about international backlash. Improved cross-Strait relations thus rely on circumventing this quintessential commitment problem in international politics.

This study analyses the “one China” framework's significance for Japan–Taiwan relations since Tokyo switched diplomatic recognition from Taipei to Beijing in 1972. Drawing on Chinese-, Japanese- and English-language sources, it examines developments since the breakthrough Japan–PRC normalization communiqué and the “Japan formula,” which enabled Tokyo to normalize relations – six years before Washington – without recognizing Beijing's claim of sovereignty over Taiwan, and while maintaining robust, if unofficial, ties with Taipei thenceforth. Highlighting distinctions between Beijing's self-asserted “one-China principle” and Japan's ambiguous official position and subsequent effective policies, it assesses incremental but practically significant evolutions of Japan–Taiwan relations over the past half-century. In the 21st century, the trend towards incrementally closer ties has proven strikingly resilient to political transitions in Japan and Taiwan, China's growing power, pushback from Beijing and worsening cross-Strait frictions. Beyond Japan–Taiwan relations and theoretical debates on “one China,” this article's findings carry significant implications for Taiwan's international space, cross-Strait dynamics and China–Japan–United States relations.

This lead article surveys the history and evolving policy legacies of the “one China” framework 50 years after US President Richard Nixon's historic 1972 visit to China. It begins by introducing key concepts and highlighting the crucial difference between Beijing's self-defined “one-China principle” and the US's, Japan's and key other countries’ variable “one China” policies as it relates to Taiwan. It argues that three seminal 1970s developments consolidated the “one China” framework as an informal institution of international politics. The ambiguity baked in by Cold War-era geopolitical necessity provided flexibility sufficient to enable diplomatic breakthroughs between erstwhile adversaries, but also planted seeds for deepening contestation and frictions today. Recent developments – especially Taiwan's democratization and Beijing's increasingly bold and proactive assertion of its claim to sovereignty over Taiwan – have transformed incentive structures in Taipei and for its major international partners. The net effect is that the myth of “consensus” and the ambiguities enabling the framework's half-century of success face unprecedented challenges today.