This is a cold thing to say, but too many countries have an interest in keeping Syria a cauldron of chaos—as long as the brew doesn’t boil over to other countries. Which is why focusing on ISIS in Iraq is a more promising possibility.

Obama’s May 28 speech at West Point is worth a second look. Many pundits derided it at the time as insufficiently “robust,” but his main point was to redefine the idea of American strength and leadership—to note that not every global problem has a military solution and that some of America’s costliest mistakes have stemmed from rushing to arms “without thinking through the consequences, without building international support and legitimacy for our action, without leveling with the American people about the sacrifice required.”

He drew a distinction in the speech that seems obvious until you realize how few American politicians observe it. There are “core interests”—direct threats to America and its allies, which we would certainly defend with military force, “unilaterally if necessary.” And there are crises that may “stir our conscience or push the world in a more dangerous direction” but don’t threaten our core interests. In these latter cases, “the threshold for military action must be higher,” and if force is used, “we should not go it alone,” for the pragmatic reason that “collective action in these circumstances is more likely to succeed, more likely to be sustained, and less likely to lead to costly mistakes.”