Russian forces invaded Ukraine early on February 24, 2022, following an ominous yearlong military buildup and 30 years of Ukrainian independence after the Soviet Union fell apart in December 1991. The country of nearly 45 million people, assaulted from Belarus to the north, Russia to the east, and Russian-controlled Crimea in the south, is strategically positioned between Russia and the rest of Europe—including a swath of eastern European nations once under the Soviet sphere that have since joined the North Atlantic Treaty Organization, an expansion of the Western defensive alliance that Russia views as a profound threat.
Russian interventions in other former Soviet-bloc countries have led to several still disputed regions known as “frozen conflict” zones, including along Ukraine’s border. Ukraine has deep historical and cultural ties with Russia. But its efforts to throw off Russian domination in recent years have resulted in losses of Ukrainian lives and territory. This includes the Crimean Peninsula, annexed in 2014, followed soon after by Russian seizures of large regions of eastern Ukraine—and, now, in early 2022, an assault on the entire country.
Ukraine declares independence as the Soviet Union is collapsing in 1991.
Ukraine joins a collaborative partnership with NATO. It gives up its nuclear arsenal in exchange for a signed agreement from Russia, the U.S., and the U.K. to protect its sovereignty.
Disputed elections in Georgia in 2003 and Ukraine in 2004 set off Georgia’s “Rose Revolution” and Ukraine’s “Orange Revolution” protesting corruption and Russian influence.
Ukraine and Georgia begin to pursue membership in the NATO alliance. Later that summer, Russia backs separatists in breakaway regions of Abkhazia and South Ossetia. Ukraine begins talks to form ties with the European Union.
Protests erupt in Kyiv’s Maidan Square over the government’s withdrawal from EU talks. More than 100 protestors are killed; the Moscow-backed Ukrainian president flees to Russia.
Russia seizes control of the Crimean Peninsula and annexes the territory.
Pro-Russian separatists seize control of parts of Ukraine’s eastern regions of Donetsk and Luhansk; the 2015 Minsk II peace agreement quells some of the violence, but the region suffers more than 13,000 casualties by the end of 2021.
In 2019 Ukraine passes a constitutional amendment to pursue NATO and EU membership. The following year it becomes a NATO Enhanced Opportunities Partner, cooperating on missions and exercises.
Russia builds up a massive military presence along Ukraine’s border. Russian president Vladimir Putin orders troops into separatist-held parts of Donetsk and Luhansk and recognizes the regions as independent. On February 24, 2022, Russia begins a full assault on Ukraine by land, air, and sea.
Russian-backed disputed regions also exist in other areas of the former Soviet Union, including Georgia and on Moldova’s eastern border with Ukraine.