Maj. Gen. Darryl A. Williams, U.S. Army Africa commander and Brig. Gen. Daniel Dee Ziankahn, chief of staff of the Armed Forces Liberia, engage in a discussion during an Operation United Shield rehearsal of concept brief in Monrovia, Liberia. The Armed Forces of Liberia and the U.S. formed a combined command known as United Shield to construct Ebola treatment units as part of the Operation United Assistance. The U.S. Agency for International Development is the lead U.S. Government organization for Operation United Assistance. U.S. Africa Command is supporting the effort by providing command and control, logistics, training and engineering assets to contain the Ebola virus outbreak in West African nations.