Securing guarantees: How nuclear proliferation can strengthen great power commitments

How does expanding the nuclear club alter the structure of the international system? The structure of alignments in the international system clearly shapes nuclear proliferation, as great powers often pressure subordinates into eschewing nuclear pursuit. What remains unclear, however, is how nuclear acquisition by subordinate states can, in turn, affect these alignments. I use a formal model to show that including great powers’ preferences after their allies have acquired nuclear weapons reveals a new mechanism behind proliferation: nuclear possession can allow states to change their patrons’ incentives and draw them closer, even against their wishes, thereby tightening hierarchies.