Liu, JessicaWhy do states engage in nuclear proliferation? Nuclear proliferation is a major security issue affecting the international arena. Existing studies debate the determinants of nuclear proliferation, including domestic and international circumstances. My research question considers membership in the United Nations Security Council (UNSC) as a potential correlate of nuclear proliferation. Are countries that are members of the UNSC more likely to engage in nuclear proliferation compared to countries that are not elected to the UNSC? I find that membership in the UNSC is positively correlated with advancement on the nuclear proliferation continuum. In addition, my control variable of enduring rivalry with another state also presents a positive relationship. However, a state's signatory status on the Treaty on the Non-Proliferation of Nuclear Weapons has no significant effect on proliferation. I disaggregate the steps of nuclear proliferation to obtain a more detailed understanding of how these variables affect a state's status on proliferation.en-USnuclear proliferationUnited Nations Security CouncilTreaty on the Non-Proliferation of Nuclear Weaponsenduring rivalryresearch paper