On 15 April, National Defense University's INSS Center for the Study of Weapons of Mass Destruction Assistant Policy Fellow Mr. Paul J. David-Justus and Senior Policy Fellow Dr. Kathleen Ellis, in support of the Defense Threat Reduction Agency (DTRA), facilitated a tabletop exercise demonstrating the multifaceted domestic and international challenge of countering the proliferation of WMD at the Proliferation Security Initiative (PSI) Balkans Regional Engagement in Ljubljana, Slovenia.

Co-hosted by the Republic of Slovenia and the United States, the event was attended by 62 civilian, law enforcement, and military leaders from 18 countries.