The surge worked. So declare Sens. McCain and Lieberman in today’s Wall Street Journal. They join the chorus of voices, including the Washington Post editorial board, who point to the decline in violence in Iraq that has occurred since the so-called surge went into effect as a sign that the opponents of the surge have been proved wrong.

No one disputes that the security situation in Iraq has improved. Although 2007 was the deadliest year of the war, American casualties declined sharply in the latter half of the year. We can all be thankful for that, and U.S. troops, who have once again proved remarkably adaptable, deserve much of the credit.

But as Air Force Major General Charles J. Dunlap, Jr. noted in yesterday’s New York Times, “two other uncomfortable developments also helped suppress violence. First, the Iraqi population has largely segregated itself into sectarian fiefs. Second, supposedly ‘reformed’ insurgents now dominate Anbar Province.” Dunlap wonders aloud whether these newly-empowered “Sunni partisans” have “bought into the idea of a truly pluralistic and democratic Iraq.” If they have not, and if they remain opposed to reconciliation with the Shiite majority, arming the individuals and groups might prove a short-term strategy that cuts against our medium- to long-term objectives.

In this context, we should also keep in mind that military operations should be conducted in pursuit of a specific objective, and the purpose of the surge was to make a space for political reconciliation among the Iraqi people that would, in the president’s words, “hasten the day our troops begin coming home.”

Note that the advocates of the surge, including most importantly Sens. McCain and Lieberman, don’t want the troops to come home. Certainly not any time soon, and perhaps not ever. Sen. McCain last week said U.S. troops might remain in Iraq for 100 years. President Bush and Secretary of Defense Gates have drawn parallels to Korea, where U.S. troops have been deployed since 1950. (Kudos to Slate’s Fred Kaplan for his take-down of this outrageously inapt analogy.)

In other words, the surge strategy, marketed to the American people as a vehicle for hastening the end of the U.S. military presence in Iraq, is now being used as a justification for keeping U.S. troops there. Success, once synonymous with withdrawal (remember “As the Iraqis stand up, we will stand down?”) now means something very different.

Before his victory in the New Hampshire primary, Sen. McCain crowed that the surge had been successful, allowing him to resurrect his moribund campaign. “Thank God [Iraq]‘s off the front pages,” the leading proponent for the war told reporters on board the Straight Talk Express.

But I’m betting that the vast majority of Americans are still thinking about Iraq, even if it is “off the front pages,” and their calculation of costs and benefits is very different from Sen. McCain’s. In poll after poll, a solid majority of Americans believe that we have already spent far too much blood and treasure in Iraq, and they aren’t going to passively accept another 100 years in Iraq, at a cost of $100 billion or more every year. And what of the human costs? The strains on our military from two or three or four combat tours are already plainly visible. How will we maintain, over a period of many decades, an army of citizen-soldiers who spend more time in a foreign country than they do in their own?

Sens. McCain and Lieberman may believe that staying in Iraq indefinitely is synonymous with success. For most Americans, the opposite is true: we will have succeeded when we have brought the troops home safely, and we are no closer to that goal than we were one year ago.