LAUSR

Abstract Do trade barriers help slow the spread of nuclear weapons? Supply-side controls on proliferation equipment and material are often dismissed as ineffective because nuclear weapons–seeking states can develop methods to circumvent the controls. However, these global export controls have important secondary effects. By creating barriers to trade, export controls force states to develop costly and inefficient methods that interfere with progress toward nuclear weapons development. Using case evidence beginning with the advent of the Nuclear Suppliers Group’s export control regime in 1974, I argue that the resulting delay and frustration can change leaders’ strategic calculations regarding the value of their nuclear weapons programs. These findings demonstrate that proliferation controls do slow the spread of nuclear weapons, both by delaying existing programs, and by decreasing the likelihood that leaders will make decisions to continue with, or even start, nuclear weapons programs.