U.S. Service Members and civilian contractors prepare to board an MV-22B Osprey with SPMAGTF Crisis Response - Africa as part of the Marines final mission in support of Operation United Assistance in Monrovia, Liberia, Dec. 1, 2014. United Assistance is a Department of Defense operation that provides command and control, logistics, training, and engineering support to U.S. Agency for International Development- led efforts to contain the Ebola virus outbreak in West African nations. (U.S. Marine Corps photo by Lance Cpl. Andre Dakis/SPMAGTF-CR-AF Combat Camera/Released)