Annexation of Crimea

Unmarked Russian soldiers ("little green men") seized control of Crimea in February–March 2014 following the ouster of Ukraine's pro-Russian president Viktor Yanukovych. Russia then staged a referendum on joining Russia under military occupation, widely condemned as neither free nor legal by the UN General Assembly, the OSCE, and most of the international community, and formally annexed the peninsula on 18 March 2014 — the first forcible annexation of European territory since the Second World War.