The collective goods theory of alliances and neorealist theory yield conflicting expectations about the security policies of states. The former emphasizes the temptation to “ride free” on the efforts of others, while the latter emphasizes the incentives for self-help. In the cases of Britain, China, and France during the early cold war, the constraints identified by neorealist theory, reinforced by the advent of nuclear weapons, prevailed. Each discounted the value of the security benefits superpower partners could provide. The second-ranking powers' decisions to shoulder the burden of developing independent nuclear forces are at odds with collective goods arguments that portray especially strong temptations to ride free in the circumstances that prevailed at that time—an international system dominated by two superpowers, each possessing large nuclear deterrent arsenals that could easily be employed on behalf of allies. This analysis suggests that present efforts to discourage additional states from acquiring nuclear weapons by offering them international security guarantees are unlikely to succeed.