U.S. Marine Corps Lt. Col. Trevor Hall, second from left, the battalion commander of the 3rd Battalion, 8th Marine Regiment and Black Sea Rotational Force 14-2, speaks with U.S. Sen. John McCain of Arizona, right, U.S. Sen. John Hoeven of North Dakota, center, and U.S. Sen. John Barrasso of Wyoming, left, about exercise Summer Shield, a joint staff planning live-fire maneuver event designed to enhance the NATO force's capacity and capability to integrate combined arms and maneuver at the battalion and brigade level, at a range near Camp Adazi, Latvia, April 15, 2014. Black Sea Rotational Force is an annual multilateral security cooperation activity between the U.S. Marine Corps and partner nations in the Black Sea, Balkan and Caucasus regions designed to enhance participants collective professional military capacity, promote regional stability and build enduring relationships with partner nations.