According to the polls, a little more than a majority of Americans oppose intervention in Syria, although it is difficult to say exactly what this means since the subject is decidedly ambiguous. Does intervention mean the sort of limited air campaign that President Obama seems to have in mind, or does it mean “boots on the ground” and indefinite occupation? Not an easy question to answer.

It is disingenuous to say that intervention is out of the question since the American people are “weary of war.” Of course they are weary of war; most human beings grow weary of war fairly quickly. But Americans were undoubtedly weary of war 70 years ago, in 1943, or 150 years ago, in 1863, and with tens of thousands of good reasons. The difference is that, in both instances, they were guided by presidential leadership, and some semblance of coherence in making the case for war. By starting and stopping and starting again, above all by issuing declarations on one day and repudiating them the next, President Obama has failed an essential test of his office in the Syrian crisis. This has weakened Obama’s authority; more important, it has diminished American leadership in the world.