Commentary With desperate Afghans clinging to departing American airplanes, the fall of Afghanistan is being compared to the American evacuation of Saigon in 1975. The Taliban takeover may also preview how President Joe Biden would handle a military confrontation with China, perhaps over Taiwan. As vice president, Biden got control of China policy through the work of longtime Democrat activist Thomas Donilon. Despite a questionable record as a lobbyist with Fannie Mae, then President Obama picked Donilon for national security adviser, which even troubled leftist writers such as Robert Scheer of Truthdig. In “Duty: Memoirs of a Secretary at War,” Robert Gates wrote that Donilon characterized the U.S. military as “in revolt” and “insubordinate.” Donilon “bridled” when Gen. Stanley McChrystal announced a “counterinsurgency” strategy in Afghanistan. It disturbed Donilon that U.S. troops might actually defeat their enemies. But Donilon was soft on China. The Biden loyalist disagreed that “a rising …