A prominent Obama administration trade advisor is one of the central players in a series of scandals and ethical rows that have reportedly placed him in cahoots with corrupt Congolese warlords and other questionable figures. Kase Lawal, an oil mogul with longstanding ties to the Clinton family, was appointed in 2010 as a member of Obama’s Advisory Committee for Trade Policy and Negotiations. Since his selection to the trade board, Lawal has become enmeshed in a pact to purchase large quantities of illegal gold from a violent Congolese warlord, according to a U.N. investigation and various reports. The crooked gold...