U.S. Marines with the Combined Arms Company, Black Sea Rotational Force familiarize Bulgarian Soldiers with the M-777 Howitzer artillery cannon during Platinum Lion 16-2 at Novo Selo Training Area, Bulgaria, Jan. 7, 2016. Exercise Platinum Lion increases readiness and demonstrates our collective ability to operate as a single force committed to protecting the sovereignty of NATO allies and other European partners. (U.S. Marine Corps Photo by Cpl. Justin T. Updegraff/ Released)

The United Kingdom’s Royal Navy’s flagship, the HMS Ocean, positioned herself alongside other ships during the photo exercise showcasing the amphibious assets for BALTOPS 2015, June 8, 2015. The exercise is an annually recurring multinational exercise designed to enhance flexibility and interoperability, as well as demonstrate resolve of allied and partner forces to defend the Baltic region (U.S. Marine Corps photo by 1st Lt. Sarah E. Burns)

U.S. Marine Sgt. Steven Mashburn, a squad leader with Black Sea Rotational Force, right, holds the American flag during the opening ceremony for Exercise Saber Strike at the Pabrade Training Area, Lithuania, June 8, 2015. The exercise brings NATO and other partner nations together for a multilateral training event designed to promote regional stability and security, strengthen partnerships, and foster trust. (U.S. Marine Corps photo by Sgt. Paul Peterson/Released)

U.S. Marine MV-22B Ospreys from Special-Purpose Marine Air-Ground Task Force Crisis Response-Africa departed Mihail Kogălniceanu Air Base, Romania, with a platoon of Marines from the Black Sea Rotational Force to support a multilateral training exercise during Platinum Eagle 15, May 26, 2015. The Ospreys left Morón Air Base, Spain, earlier in the week, and arrived to work with their allies from the Bulgarian and Romanian armed forces. The Ospreys delivered the Marines to the Babadag Training Area, where they demonstrated their ability to conduct security operations. The training represents the first time Ospreys have conducted multilateral training in Romania, where members of BSRF have established a growing relationship with partner Romanian forces. (U.S. Marine Corps photo by Sgt. Paul Peterson/Released)

Icelandic Coast Guard Rear Admiral Georg Lárusson, U.S. Air Force Maj. Gen. Randy Kee and Norwegian Army Maj. Gen. Odin Johannessen listen to a presentation during the Arctic Security Forces Roundtable, May 12, 2015 in Reykjavik, Iceland. Kee and Johannessen co-led the conference, while Lárusson led coordination of host nation support. Representatives from 11 nations across Europe and North America met for the ASFR in order to promote regional understanding and enhance multilateral security operations within the Arctic area.