For weeks, Western officials warned that a massive buildup of Russian troops on the border with Ukraine signaled a plan by Moscow to invade. A full-scale Russian invasion is now underway. There are missiles and artillery hitting major cities and hundreds of people being killed. Some places, including Ukraine’s biggest nuclear power station , are already under Russian control.
The war has produced more than 1.3 million refugees since it began on Feb. 24, according to the United Nations refugee agency, and is upending decades of peace in Europe.
Russian President Vladimir Putin has said that he seeks to “demilitarize” Ukraine and ensure that it stays out of NATO, whose expansion he sees as a security threat to Russia. Moscow has been the victim of severe international sanctions, which have crushed Russia’s currency . This has sparked a flight of foreign brands and investors from the country.
Here’s what we know about why Russia has attacked Ukraine — and what could come next.