There are comical elements in the current Turkish invasion of northern Syria. Its name, for example: Operation Olive Branch. Or the frantic back-pedalling by U.S. Secretary of State Rex Tillerson about the announcement that triggered (or at least provided a pretext for) the Turkish offensive. A week ago the U.S. declared it was building a new 30,000-strong “border security force” in the territory controlled by the Syrian Kurds along the Turkish border.