U.S. Army Maj. Gen. Darryl Williams and Ambassador Deborah R. Malac, the U.S. Ambassador to Liberia, walk to board an U.S. Marine Corps MV-22B Osprey assigned to Special-Purpose Marine Air-Ground Task Force - Crisis Response - Africa, at the U.S. Embassy in Monrovia, Liberia, Oct. 13, 2014. Operation United Assistance is part of a comprehensive U.S. Government effort, led by the U.S. Agency for International Development, to respond to and contain the outbreak of the Ebola virus in West Africa as quickly as possible. (U.S. Marine Corps photo by Lance Cpl. Andre Dakis/SP-MAGTF Crisis Response - Africa Combat Camera/Released)