Dressed in military camouflage with an assault rifle at the ready, "Prof" Yeh peers from behind a vehicle in a parking lot outside Taipei, scanning his surroundings and waiting for a signal to advance. Yeh actually works in marketing, and his weapon is a replica -- but he is spending the weekend attending an urban warfare workshop to prepare for what he sees as the very real threat of a Chinese invasion. "The Russia-Ukraine war is a big reason why I came to this workshop," 47-year-old Yeh, whose call sign during training is "Prof", tells AFP during a break between...