Long before the invasion of Ukraine, the Kremlin has taken steps toward the institutionalisation of hybrid warfare as its primary instrument of foreign policy. The Kremlin’s geostrategic goals remain identical to those pursued during the Cold War, and achieving supremacy in the Black Sea is a critical prerequisite for attaining these goals. Russia relies on a complex arsenal of tools for interference and destabilisation and deploys these tools in a concerted manner to fracture internal unity and integrity within EU and NATO through political manipulation and economic bullying. Bulgaria and Romania are among the most frequent targets of the Kremlin’s wide-ranging destabilisation tactics. The two countries have suffered the effects of prolonged Russian malign interference, which has manifested itself in the spread of disinformation and propaganda, cyber-attacks against institutions and critical infrastructure, state capture and political meddling, and encroachment of their exclusive economic zones (EEZ).

This policy brief examines Russia’s renewed interest in unconventional weapons as a means of power projection which includes the use of state-sponsored targeted assassinations involving hard-to-detect chemical, biological, or radioactive substances. The Kremlin uses disinformation campaigns that exploit issues related to weapons of mass destruction (WMD) against the countries in the Black Sea region as a form of cognitive warfare designed to advance Russia’s geopolitical agenda by preying on public anxieties. Black Sea regional security cooperation, strategic engagement with EU and NATO partners, and enhanced institutional capacity at the national level to combat media capture and disinformation are critical for harmonising the efforts to deter and counter the Kremlin’s hybrid warfare strategy and bolster the region’s defence capabilities.