When the USSR collapsed, its nuclear arsenal was scattered across Russia, Belarus, Kazakhstan, and Ukraine. For the US administration, the priority was to prevent the emergence of new nuclear powers as a result of the Soviet dissolution.
Negotiations began between Ukraine and the United States over the terms for the transfer and dismantling of the arsenal on Ukrainian territory: around 2,500 tactical warheads and 1,500 warheads deployed on intercontinental ballistic missiles (ICBMs), representing nearly 17% of Soviet capabilities. By acceding to the Non-Proliferation Treaty (NPT), Ukraine officially became a non-nuclear-weapon state and, in exchange, received security assurances from the United States, Russia, and the United Kingdom with the signing of the Budapest Memorandum on December 5, 1994. On the same day, France and China made similar commitments through separate unilateral declarations.
What influence did the process of devolving the Soviet nuclear legacy have on the prospects for Ukraine’s integration into the Euro-Atlantic security architecture during the 1990s? Did Paris, London, and Bonn give as much importance to the “Ukrainian question” as Washington did? Was there genuine coordination between Europeans and Americans, or, on the contrary, divergent views on the terms of Ukraine’s participation in regional security structures?
These are among the questions explored by Julien Dubois, a PhD student in contemporary history at CIENS, as part of his thesis co-supervised by Frédéric Bozo (Sorbonne Nouvelle, ICEE) and Frédéric Gloriant (CIENS, IHMC). He presented his initial findings during a CIENS workshop held on July 2, 2026.
Alongside his research, Julien Dubois is also studying Ukrainian language at INALCO — an approach that responds to a gap: primary sources and Ukrainian scholarly literature remain underused in French historiography, and Ukrainian decision-making has often been pushed into the background. Yet, he stresses, it is essential to revisit these debates to better understand the arguments, the trade-offs, and the decision-making mechanisms that led Ukraine to renounce nuclear weapons, as well as to shape its policy of integration into an alliance model capable of guaranteeing its security.
His research aims at analyzing the various proposals put forward by Ukrainian authorities and assessing their influence on negotiations with European, American, and Russian counterparts. It also seeks to evaluate the concessions obtained by Ukraine, to question its degree of agency in this process, and to understand how these negotiations helped partly reshape the post–Cold War alliance system.
Photo caption: Destruction of a Kh-22 cruise missile as part of the Cooperative Threat Reduction program at the Ozerne base in Ukraine on March 29, 2004. Credit: ©Defense Threat Reduction Agency
