In November 2018, Petro Poroshenko, who was clearly on the election campaign trail, tried to create a scandal to appeal again to the West and show how Russia is treating him and that new sanctions are needed.
The [Ukrainian] warships secretly tried to sneak through the Kerch Strait by entering [Russian] territorial waters, the part that was Russia’s territorial waters before the referendum in Crimea.
On November 25 border patrol boats belonging to Russia’s FSB security service seized two small Ukrainian armoured artillery vessels and their crews after shooting at them, wounding several Ukrainian servicemen. Russia argued that they were in Russian waters.
However, a bilateral treaty between Russia and Ukraine, signed in 2003 and ratified by Russia in 2004, governs the use of the Kerch strait and the Sea of Azov, which in the treaty is considered to be the “internal waters” of both Russia and Ukraine.