Kerch Strait incident
An international incident occurred on 25 November 2018 when the Russian Federal Security Service (FSB) coast guard fired upon and captured three Ukrainian Navy vessels after they attempted to pass from the Black Sea into the Sea of Azov through the Kerch Strait on their way to the port of Mariupol. In 2014, Russia had annexed the nearby Crimean Peninsula, which is predominantly internationally recognised as Ukrainian territory. It later constructed the Crimean Bridge across the strait. Under a 2003 treaty, the strait and the Azov Sea are intended to be the shared territorial waters of both countries, and freely accessible. Russia, in turn, insists that, while the 2003 treaty remains legally valid, Ukrainian ships must ask for permission before entering Russian waters along the perimeter of Crimea as any transnational water crossing, as regulated by the Law of the Sea Treaty. The annexation of Crimea by Russia is not recognized by Ukraine, therefore Ukraine holds that the invocation of an international treaty with regards to Crimean waters is illegitimate. 