How NATO is defending Eastern Europe
After years of defense cuts following the end of the Cold War, the North Atlantic Treaty Organization (NATO) changed tack after Russia's annexation of Crimea in 2014.
Defense spending increased, and the alliance boosted its presence in Eastern Europe in 2017.
As Russia ringed Ukraine with forces in February, NATO responded by sending even more troops and equipment to the region.
Russia's President Vladimir Putin has complained about NATO's expansion, claiming it's a major reason decided to invade Ukraine.
Watch the video above to find out what NATO is doing to counter Russia.