WASHINGTON (Reuters) – The U.S. Navy dock landing ship Gunston Hall left port on Wednesday to mark the first movement for the largest NATO exercise since the Cold War, officials said. WHAT IS HAPPENING Some 90,000 troops from the United States and fellow NATO allied nations are due to join the Steadfast Defender 2024 drills that will run through May. More than 50 ships from aircraft carriers to destroyers will take part, as well as more than 80 fighter jets, helicopters and drones and at least 1,100 combat vehicles including 133 tanks and 533 infantry fighting vehicles. The drills will rehears…