When is a tweet just a tweet?
A debate is percolating in the U.S. State Department, where diplomats measure their words with demitasse spoons, on how to handle Donald Trump's Twitter commentary if he continues to tweet after he becomes U.S. president on Jan. 20.
By tradition, anything the president says is regarded as U.S. policy and can be repeated to foreign officials without fear of contradiction, at least from the White House.