(AP Photo/Vadim Ghirda) US Army 2nd Battalion, 10th Regiment, 10th Brigade UH-60 Blackhawk helicopters take off during a joint US-Romanian air assault exercise at the Mihail Kogalniceanu airbase, eastern Romania, Wednesday, March 8, 2017. Romanian and U.S troops are staging joint exercises with U.S. Black Hawk helicopters, part of the 10th Combat Aviation Brigade nine-month rotational deployment in support of Operation Atlantic Resolve, which aims to reassure NATO's European allies in light of Russia's invasion in Ukraine.