Do U.S. security commitments discourage nuclear proliferation?

Abstract

U.S. policy makers claim that nuclear weapons are needed to guarantee security commitments and discourage the international spread of nuclear weapons. This thesis evaluates the link between security guarantees and efforts to prevent nuclear proliferation. It draws three conclusions based on case studies of the use of conventional security commitments and nuclear security guarantees to prevent nuclear weapons development in South Korea and Taiwan. First, nuclear security guarantees alone are not sufficient to prevent proliferation. Second, strong conventional commitments made credible by visible presence of forces are sufficient to prevent nuclear proliferation when the direct security threat is conventional. Third, when the security threat being faced includes nuclear weapons, nuclear proliferation prevention requires both a nuclear security guarantee and a physically evident conventional military guarantee. Two implications for security policy follow from these findings. First, nuclear weapons are necessary in the modem security environment. Second, nuclear security guarantees are not credible without the stationing of conventional forces