U.S. Marines with Black Sea Rotational Force (BSRF) 14 flip a tire during a squad competition in Mihail Kogalniceanu, Romania, Jan. 17, 2014. 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.