President Trump left for the Middle East and Europe today, amid a domestic firestorm that is fanned by concerns over intelligence leaks and hints of obstruction of justice. Leaving home for foreign lands may seem to be just what the president needs, and his advisers can be forgiven for believing that a respite from domestic politics could be useful: Mr. Trump will probably be well received by foreign leaders, particularly those in the Middle East.
But there are lessons from history that suggest that using international trips to quell investigations at home doesn’t work. Indeed, when President Richard Nixon went to