Marines with the 31st Marine Expeditionary Unit embark aboard the USS Green Bay (LPD 20), White Beach Naval Facility, Okinawa, Japan, Feb. 1, 2017. Detachments from the air, ground and logistics combat elements of the 31st Marine Expeditionary Unit embarked Feb. 1, 2017 as a part of the MEU’s 17.1 Spring Patrol. The air-ground task force concept is designed to thoroughly exploit the combat power inherent in air and ground assets by closely integrating them into a single force under one commander. The MEU brings what it needs to sustain itself from the sea for the rapid accomplishment of the mission or to pave the way for follow-on forces. The size and composition of the MEU makes it well suited for amphibious operations, security operations, noncombatant evacuation operations, humanitarian assistance operations and special operations. (U.S. Marine Corps photo by Sgt. Tiffany Edwards/Released)