Beijing claims the democratically-governed island as its own and has vowed to bring it under Chinese control, by force if necessary. Mullen, a retired Navy admiral who served as the top U.S. military officer under former presidents George W. Bush and Barack Obama, was being accompanied by Meghan O’Sullivan. O’Sullivan was a former deputy national security advisor under Bush, and Michele Flournoy, a former undersecretary of defence under Obama. Two former National Security Council senior directors for Asia, Mike Green and Evan Medeiros, are also on the trip, which is intended to “demonstrate our continued robust support for Taiwan,” a…