Asian shares and U.S. futures tumbled on Tuesday after a tumultuous Wall Street session, with investors nervous about the situation in Ukraine and eyeing the U.S. Federal Reserve amid worries about a move to tighter monetary policy globally. NATO said on Monday it was putting forces on standby and reinforcing eastern Europe with more ships and fighter jets, in what Russia denounced as Western "hysteria" in response to its build-up of troops on the Ukraine border. MSCI's broadest index of Asia-Pacific shares outside Japan shed 1.2%, falling to its lowest in a month, and Japan's Nikkei skidded 2% to its lowest ... (full story)