We have just witnessed one of the most stunning and humiliating climb downs of any president in the history of the United States. Obama's humiliation is entirely of his own making. He unilaterally threatened to wage war, however limited he said it would be, for no clear purpose, with no clear strategy and with no clear outcome. He did so thoughtlessly by proclaiming a "red line" and thus backing himself through inadvertence and, more important, his country into an untenable position. He pushed the country out onto a limb only to find he was alone, without allies, without Congress, even...