Sailors and Marines assigned to the Iwo Jima Amphibious Ready Group and embarked elements of the 24th Marine Expeditionary Unit conduct visit, board, search and seizure exercises aboard the Military Sealift Command maritime prepositioning ship USNS SGT William R. Button during Exercise Eager Lion 2012. The exercise is designed to strengthen military-to-military relationships through a joint, multinational approach to meet current and future complex national security challenges, including 19 countries from five different continents and more than 11,000 participants..