It is quite possible that Monday's meeting in the White House could prove even more crucial to the future of Ukraine - and for all of Europe's security - than last Friday's US-Russia summit in Alaska. On the surface, that Putin-Trump reunion seemed to live down to every expectation.

Donald Trump was not. When the leaders of Russia and the United States shook hands on stage after failing to reach a deal at their Alaska summit, President Trump had a look on his face that his four predecessors might have recognized after their own encounters with the former KGB agent who has defied the world in his determination to rebuild an empire.