U.S. Marines with Black Sea Rotational Force (BSRF) 14-2, Latvian soldiers and an Estonian service member take questions from a class at a secondary school in Lejasciems, Latvia, during Summer Shield April 9, 2014. Summer Shield was a joint staff planning and combined-arms, live-fire maneuver event designed to enhance the Latvian Land Force's capacity and capability at the battalion and brigade levels. BSRF 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.