Constants have vanished

For Syrian Kurds, the stance of the president of the United States is like a "stab in the back." Who can trust the US, they say, when Donald Trump had no qualms about giving Turkish President Recep Tayyip Erdogan the green light to invade Syria and occupy territory controlled by his allies in the war on the Islamic State (ISIS). 

The message is clear: The decisions of the superpower are not based on some long-term strategy hammered out by the US State Department, the Pentagon and the White House. Rather, they are animated by the impulse and the unbearable lightness of a president who is willing to do anything to ensure his re-election. 

The problem is, if America's Kurdish allies are so easily abandoned to their fate, what could other US allies, who have not lost 11,000 fighters in battle, possibly expect from Washington? 

The European Union does not inspire...