President Trump and his administration have always had a mixed-messaging problem. Whether it had to do with the future of NATO, relations with the European Union, a rapprochement with Russia or a trade war with China, Mr. Trump has made norm-shattering pronouncements while his top advisers worked behind the scenes to preserve the status quo.

Most recently, his insistence that Congress pony up $5.7 billion for a wall at the southern border and his threat to keep the federal government closed for “months or even years” if he doesn’t get his way have undermined Vice President Mike Pence’s efforts to reach a compromise over the shutdown with Democratic lawmakers.

But the president’s mercurial approach to the conflict in Syria is in a category all its own. After Mr. Trump stunned the world last month by ordering the withdrawal of all 2,000 American troops in Syria within 30 days, the administration began backtracking almost immediately.

By the time John Bolton, the national security adviser, visited Israel over the weekend, the president’s order was effectively reversed. Mr. Bolton laid down conditions, including the complete defeat of the Islamic State and guarantees from Turkey that it won’t attack America’s Kurdish allies. In other words, American troops are there to stay for months, or years, or indefinitely.