Giddy with joy at their sudden good fortune, the Democrats have set out to embarrass the president, pushing resolutions of less-than-no-confidence, clubbing his Iraq surge plan as it lies in its cradle, and declaring defeat in advance. In some sense, they have achieved their objectives: They have embarrassed Bush, exposed his weakness, and won over a cadre of frightened Republicans. But they have also painted themselves into a number of corners, from which they may find it hard to escape.

If Iraq is stabilized this side of chaos, the congressional Democrats will be remembered as the people who fought to prevent it, who tried to kneecap the commander and demoralize the armed forces, and all in all make the mission more difficult. If, on the other hand, the surge is seen to fail, they will be the ones who made it more difficult, demoralized the armed forces, kneecapped the commander, and telegraphed to the enemy that our will was cracking, and we would shortly be leaving.

The Democrats have also given Bush a partial alibi for a possible failure--he tried, but at a critical moment they threw in the towel. This argument would be plausible enough to attract support from a great many people. Had they let the surge play itself out, with best wishes but grave reservations, the Democrats could have gained a reputation for good will in any event, and for genuine prescience in the case of failure. But there is a difference between warning of failure and seeming to want it or cause it, and this is the line they have stumbled over. They have cut themselves off from all share in a victory, bought themselves a half-share in a loss, should one develop, and given the president they so despise an excuse he did not have before this. If a failure ensues, it is no longer his fault, in its entirety. Now it is his fault--and theirs.

And why is it now at least partly their problem? Because the Democratic tantrum comes at just the wrong time. For the first time in years, Bush has gone back on the offensive (which is where most of his disaffected supporters have longed to see him), and for the first time in a long time we may see some results. "The mere suggestion of a serious crackdown has prompted its targets to run for cover," writes the Boston Herald's Jules Crittenden. "Moktada al-Sadr is angling to get back into the political process. His Shiite militia men have hidden their weapons and are trying to act normal. Sunni insurgents are reportedly hightailing it to Diyala. Iran has signaled it wants positive engagement and negotiations, and is trying to look like a friendly neighbor to Iraq."

From the start, Bush's tendency in Iraq, when faced with a complex mix of political and military problems, has been to emphasize the political aspect, trying to engage or negotiate with people and agents who in retrospect should have been intimidated, disposed of, or otherwise crushed. Now he has altered course: The most important part of his new plan is not the number of men to be added, but the way they will be used--not only to train the Iraqis but to engage and dispose of the enemy.

A conservative who at times has been all too compassionate, Bush has at last been cured of his fancy that he could fight a soft and compassionate war. It is a fancy Americans have been frequently loath to concede. "For some reason, this is a lesson that the U.S. seems to have to learn anew every war," writes the retired Army major and blogger Donald Sensing. "It wasn't until 1863, for example, that the Union Army finally came to understand that the [Confederate] army would not be defeated until it had been vanquished in the field, one time after another, over and over again. U.S. Grant was the first Union general to understand this fact, for which President Lincoln rewarded him with command of all the Union armies in the field."