2021–2022 Russo-Ukrainian crisis

The 2021–2022 Russo-Ukrainian crisis was a military buildup and international crisis between Russia and Ukraine. It started on March 3, 2021 and escalated in late 2021, when NATO told the Kremlin that they would support Ukraine. The crisis has caused international tension, also involving NATO, the European Union, the Lublin Triangle, the Union State, the Commonwealth of Independent States and the CSTO.
The crisis has been described as one of the most intense since the Cold War.
The crisis ended on 24 February 2022 when Russia invaded Ukraine.