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Nuclear Alliances and the Logic of Extended Deterrence

April 19, 2021


Eliza Gheorghe, Assistant Professor of the International Relations, Bilkent Universit
John Harper, Senior Adjunct Professor of American Foreign Policy; Professor Emeritus, SAIS Europe

The event began with an introduction of Gheorghe, highlighting her innovative contributions to the fields of grand strategy and nuclear alliances. During the discussion, Gheorghe focused on the question of how nuclear alliances function. She first explained that up to this point we have only considered nuclear alliance to be unbalanced alliances, such as NATO or the Warsaw Pact. But the nature of nuclear alliances she argued, is not fully explained by traditional neorealist, regime type, or liberal-institutionalist models. Rather, she proposed that it is key to look at the intra-alliance balance of power to explain how nuclear alliances offer security to their participants.

Balance of power in the context of Gheorghe’s discussion referred to the distribution of capabilities among members of the nuclear alliance. She defended the use of the term by noting that member states in the alliance will think in terms of relative power. Harper supported this claim by explaining how Europeans sometimes resented the unequal balance of power with the United States in nuclear alliances, which is only possible if we accept that there are power differentials in an alliance. If we accept this assumption about the unequal distribution of power within the alliance, then there are three structures: (1) imperial alliances, (2) hegemonic alliances, (3) balanced alliances.

Imperial alliances occur when the leading power (dominator) is overwhelmingly more powerful than all other member states (dependents) combined. This form of alliance was seen in NATO from 1945-1954, with the United States dominating Western Europe and Canada, and in the pre-Warsaw pact period from 1945-1956, with the USSR dominating Eastern Europe. The end strategy of a nuclear straitjacket was similar in both cases, as were the coercive and dismissive behaviors by the leading power towards its dependents. Both the United States and the USSR tried to thwart the development of nuclear weapons by other members of their respective alliances, suppressed or averted defections, and routinely dismissed requests for nuclear sharing, consultation, and rotational command.

Gheorghe noted that a shift to a hegemonic structure took place in the mid-1950s that would last until the end of the Cold War in 1989 for both alliances. In this case, the leading power (hegemon) remained much more powerful than any other single member, but that gap was narrowed when considering the combined capabilities of all junior partners. This led to more intra-alliance tensions as junior partners increasingly were able to assert themselves, as evidenced by France leaving the NATO military command in 1966 and Albania’s departure from the Warsaw pact in 1968. Both hegemons continued to engage in heavy coercion and dismissal behaviors, endeavouring to prevent allies from getting nuclear weapons, and subordinating those that did by making them operationally reliant on the hegemon. No multilateral force emerged from either alliance and requests for nuclear sharing beyond stationing on state territory and rotational command were swept under the table. Two behaviors the superpowers did have to adopt in this period were consultation and accommodations. The NPG for NATO and the Military Council for the Warsaw pact provided forums for junior partners to try to convince patrons to cede greater responsibilities to them. Effectively, leading states tied their security to that of their junior partners (i.e., via forward deployments and joint warfighting). Gheorghe pointed out that the most surprising discovery to come out of her research on this phase was that the behavior of the USSR suggested that the Soviets believed they would be using their nuclear warheads in cooperation with their junior partners in joint Warsaw Pact fighting.