U.S. Airmen unload expeditionary medical support equipment from a C-17 Globemaster III aircraft Sept. 30, 2014, in Monrovia, Liberia, in support of Operation United Assistance. United Assistance is a U.S. Africa Command-led operation to provide command and control, logistics, training and engineering support to the U.S. government's efforts to contain the Ebola virus outbreak in West African nations.