What was he thinking? That is the question most thoughtful observers of the U.S.-Japan alliance grappled with last week as Japanese Prime Minister Abe Shinzo fumbled questions about the imperial Japanese government’s role in recruiting “comfort women” during the Pacific War. His responses came close to undoing the progress he had made in restoring relations with China and South Korea and threatened to drive a wedge between Tokyo and Washington. They reveal uncomfortable truths about – but facts that the U.S. must nonetheless acknowledge when dealing with its ally.