Cornerstone is a two-phase exercise.
During phase I, Army National Guard and Marine Reservists will conduct combat engineering training with Lithuanian engineers. During phase II, U.S. Navy and Marine Corps personnel will work with Estonian military units to complete humanitarian construction projects. The purpose of Cornerstone is to foster a spirit of cooperation and a common understanding between participating Estonian, Latvian, and Lithuanian armed forces and the Naval, Army, and Marine forces of the United States, said Cmdr. Cornerstone provides invaluable training for U.S. Sailors, Soldiers, and Marines and those of the participating Baltic nations. It s a chance for everyone to engage in realistic and challenging training, and for U.S. personnel to interface with military counterparts in the Baltics.