By Yew Lun Tian BEIJING (Reuters) – Chinese President Xi Jinping may not have been able to stop Nancy Pelosi’s visit to Taiwan, but he ordered his country’s military to rehearse a much more aggressive step: a blockade crucial to taking the island by force, security experts say. China’s military planners have long discussed a blockade of Taiwan, but until now most likely saw practicing such a move as too provocative, security experts say. But after U.S. House Speaker Pelosi’s visit, China’s military for the first time fired missiles over Taipei, flew waves of drones over Taiwan’s offshore islan…