Members of the 22nd Marine Expeditionary Unit (MEU) board a CH-46 Sea Knight helicopter during beach-landing training during Type Commander Amphibious Training (TCAT) exercises off the coast of North Carolina. Navy and Marine Corps expeditionary forces ? integrated air, land, and sea combined arms units ? are ideally suited to meet the challenges of the 21st century security environment. They are powerful instruments of national policy and provide the National Command Authority with a multitude of diplomatic and military options to support U.S. foreign policy initiatives. U.S. Navy photo by Photographer's Mate Airman Kyle T. Voigt.