In early 2021, a buildup of Russian troops near Ukraine raised fears of an offensive. Moscow withdrew some of the forces in April, paving the way for a June summit between President Joe Biden and Russian President Vladimir Putin. Their meeting failed to meaningfully ease Russia-U.S. tensions, however.began in late October and reached an estimated 150,000 troops by the year's end.
on Ukraine's military facilities and key infrastructure. Russian troops rolled into Ukraine from Crimea in the south, all along the eastern border and from Moscow's ally Belarus, which borders Ukraine in the north.Putin argued that Russia had no choice but to act after Washington and its allies ignored its demand for security guarantees. Western leaders dismissed the claims as a false pretext for the attack.
While Russia claimed it was only targeting military facilities, air raids and artillery strikes hit residential areas, schools and hospitals across Ukraine.