On 24 February 2022, Russia began a large military invasion of Ukraine, a country bordering southwestern Russia, marking a steep escalation of a conflict that began in 2014. Several officials and analysts called the invasion the largest conventional military attack in Europe since World War II.

After the Ukrainian Revolution of Dignity in 2014, Russia annexed Crimea, and Russian-backed separatist forces seized part of the Donbas, in south-eastern Ukraine, prompting an eight-year war in the region. Starting in early 2021, a Russian military buildup took place along the Russia–Ukraine border. The United States and…