A mercenary air force that became a symbol of the U.S. occupation of Iraq is back in action—this time in Central Africa, supporting a shadowy American U.S. Special Forces commando operation targeting the Lord’s Resistance Army. In late January, a source on the ground in Central African Republic spotted a Sikorsky S-61 helicopter with the registry number N408RC carrying American Special Forces troops. The LRA, a cultish band of thieves and rapists led by warlord Joseph Kony, is most active in the forested region where Central African Republic, South Sudan, and the Democratic Republic of Congo meet. In 2010, President...