For someone who preaches the importance of diplomacy and outreach, even to longtime enemies, President Obama can be awfully tough on his friends. In recent months, he has offended most of the United States’ Persian Gulf allies. “All I need in the Middle East is a few smart autocrats,” he joked privately, according to a recent profile in the Atlantic magazine. Publicly, he has said he “weeps” for Saudi and Kuwaiti children. The United States’ European allies, he complains, have grown too dependent on American firepower to keep them safe. Even the United Kingdom, a U.S. “special” partner, has received...