Securitization of Cooperation: The Three Seas Initiative in the shadow of the Russian-Ukrainian war

The Three Seas Initiative (3SI) is a relatively new format of regional cooperation in Central Europe. The main objective of 3SI activities is the development of energy, transport and digital infrastructure in the region. Following the outbreak of the full-scale Russian-Ukrainian war in February 2014, the security dimension of 3SI activities has become more important. The last 3SI Summit was held in Vilnius in April 2024. The aim of this article is primarily to analyse the military dimension of the Three Seas Initiative's activities after the outbreak of war in Ukraine in 2022. The text presents the military potential of the 3SI countries and the diversified approach of the member states to the Russian-Ukrainian war. It also analyses the Lithuanian 3SI perspective, the decisions of the Vilnius Summit and the prospects for 3SI military cooperation. Due to the relatively new nature of the research topic, the analysis focuses primarily on recently published specialist texts.