President Donald Trump has angered traditional American allies by slapping them with tariffs and pulling the United States out of international agreements such as the Paris climate agreement and the Iran nuclear deal.

This comes despite the fact that these allies have done their best to butter up Trump and play to his ego -- and one former Trump White House official tells Politico that they aren't at all surprised by the failure of France, Canada and Japan to keep the president in check.

"Trump is very selfish and I think he views flattery as a one-way street where he gets flattered and then there's no real reciprocal benefit going back the other direction," the official said. "If you’re a foreign leader you have to realize if you try to butter up Trump it doesn’t really matter, it’s a one way street."

That said, dictatorships such as Saudi Arabia have succeeded in flattering Trump and getting something in return -- largely because they can offer him material rewards in addition to kind words.

"If you’re not a despot, you can’t really be transactional," the official explained.