Nikola Vaptsarov Naval Academy hosted a five-day course dedicated to the subject of countering a weapons of mass destruction (WMD) threat in a maritime environment from 21 to 25 October 2019. The training was delivered by the Office of Defense Cooperation at the US Embassy and the Defense Threat Reduction Agency (DTRA) in partnership with the US Department of Homeland Security under the bilateral cooperation agreement with the Republic of Bulgaria. Mr Keith Falcetti of DTRA’s International Counterproliferation Program opened the course and introduced the team of instructors, comprising US Coast Guard and Homeland Security Investigations experts. Among the course participants were representatives of the MoD, the Ministry of Transport, the Bulgarian National Security Agency, the Ministry of the Interior, and the Ministry of Finance. The discussions at the course included variants for drawing up procedures for response to specific risks. “One such risk is the smuggling of dual-use items,” explained senior instructor Justin Moyers. The course participants explored the concept for countering WMD proliferation, looked into the principles of maritime security, and at the same time participated in practical exercises for recognising different threats related to WMD proliferation by sea or the security risks to maritime objects. The course enabled the participants from different Bulgarian institutions engaged with the maritime environment to establish contacts in support of their future interagency cooperation. The training contributed to better understanding of the common challenges to maritime security. The American and the Bulgarian experts exchanged information about the procedures followed by each country in the event of a risk in a maritime environment, and at the same time were given a forum to pick each other’s brains and to share good practices and lessons learned from the operations by the different institutions in the Republic of Bulgaria and the United States if America.