Russia attacked and seized three Ukrainian naval vessels in the Kerch Strait. This marked an escalation from covert operations to overt military action. It has serious implications for Ukraine's security and sovereignty. In response, Ukraine imposed martial law in several border regions. However, the international reaction has been weak. NATO called for restraint while the EU only urged Russia to restore passage. This aggression fits Russia's strategy of undermining European security and using force to challenge Ukraine's territorial integrity. Stronger diplomatic, military, and economic steps are needed to counter Russian expansionism in the Black Sea region.