TOKYO/NEW YORK (Reuters) - Asian shares slipped on Wednesday as investor concerns about rising tensions between the United States and China tempered optimism about a re-opening of the world economy.U.S. President Donald Trump said late on Tuesday he is preparing to take action against China this week over its effort to impose national security laws on Hong Kong, but gave no further details.Hong Kong shares led declines among major regional indexes, with Hang Seng falling 0.46%, though it kept a..