THEY HAVE picked up right where they had left off. Turkey’s president, Recep Tayyip Erdogan, and President Donald Trump were beaming as they shook hands at the NATO summit in The Hague on June 24th. Mr Erdogan seemed equally upbeat after their meeting, the first since Mr Trump’s return to the White House, later that day. The American president, he announced, was warming up to the idea of unblocking the sale of F-35 stealth fighters to Turkey, stalled years ago after Mr Erdogan’s purchase of an S-400 air-defence system from Russia.