NATO is launching its largest exercise since the Cold War, rehearsing how U.S. troops could reinforce European allies in countries bordering Russia and the alliance's eastern flank if a conflict were to flare up. Some 90,000 troops are to join the Steadfast Defender 2024 drills that will run through May, the alliance's top commander, U.S. Army General Chris Cavoli said on January 18. The drills will rehearse NATO's execution of its regional plans, Cavoli said, adding that the defense plans are the first the alliance has drawn up in decades and detail how it would respond to a Russian attack.