The disappearance of China's defence minister, the latest in a string of upheavals in the country's top ranks, is stoking uncertainty about President Xi Jinping's rule as an internal security clampdown trumps international engagement. The growing unpredictability could affect the confidence other countries place in the leadership of the world's second-biggest economy, diplomats and analysts say. Defence Minister Li Shangfu, who has missed meetings including with at least one foreign counterpart since he was last seen in late August, is under investigation in a corruption ...