Many years ago, longer than I care to remember, I wrote an op ed wondering aloud “Who Will Decide When We Leave Iraq?” More than five and a half years later, we still don’t know the answer to that question.

Sure, we have an agreement with the Iraqis to leave by the end of this year. All U.S. troops are supposed to be gone, although a very large diplomatic presence, including perhaps thousands of security contractors, will remain. George W. Bush presided over the negotiation of the deal, and then passed it off to his successor. When he drew down to fewer than 50,000 troops over the summer, on a path to zero by January 1, 2012, Barack Obama was merely implementing the policy. He cannot fairly be accused of doing anything other than what his predecessor would have done. If it is a mistake for Obama to preside over a troop withdrawal, then it was a mistake for Bush to negotiate one.

But maybe we’re not leaving? Defense Secretary Leon Panetta is reportedly supporting a deal for 3,000 to 4,000 troops to remain in a training capacity past the end of the year, provided a deal can be struck with the Iraqis.

Those few Americans who are still paying attention to Iraq cannot be enthusiastic about this. We have long since tired of the ruinous, pointless war. The cheerleaders for invading Iraq said it would be a cakewalk, and that the costs would be paid for by Iraqi oil revenues, not U.S. taxpayers. It has instead consumed nearly $800 billion in U.S. taxpayer dollars, claimed the lives of over 4,400 U.S. troops, and wounded many thousands more. The costs of caring for the wounded and recapitalizing equipment will likely top an additional $1 trillion.

Haven’t we had enough already?

Apparently not.

A handful of U.S. senators are appalled to learn not that U.S. troops might be staying in Iraq, but rather that the administration is contemplating a troop withdrawal. (Is this news to them?) When they learned that the administration was trying to retain a U.S. troop presence beyond the end of this year, Diane Feinstein, Joseph Lieberman, John McCain and Lindsay Graham, complained that the numbers being contemplated were insufficient. They claimed that such a draw down would imperil the fragile gains made in the country over the past few years, and expose the few troops left behind to serious harm.

That last point might be true. It isn’t clear to me why 3,000 troops makes much more sense than 30,000 or 300. But the essential fact is that the presence in Iraq, any presence, is unnecessary. Bush made many mistakes in Iraq, beginning with the decision to invade. He was correct to determine that the mission must end. It does not serve U.S. security interests to remain in that country indefinitely.

At the time when I wrote that earlier op ed, in early 2006, I pointed to President Bush’s insistence that we would only stay so long as the Iraqis wanted us there, and suggested that the Iraqs might ultimately determined whether we stayed or went. Bush might have been gambling that the Iraqis would not ask us to leave, at least not right away, and the polling data at the time suggested that was a safe bet.

It isn’t any longer. A few people here in the United States might want U.S. troops to stay in Iraq; but very few Iraqis agree.

Realist IR scholars will repeat ad nauseum the mantra from Thucydides: “The strong do what they can; the weak suffer what they must.” To the extent that this is true, no U.S. president would gamble this country’s security on the whims of a nascent parliamentary democracy rife with anti-American sentiment. We would never hand such a decision over to the Iraqis if it was truly vital to our national security to remain there.

It isn’t. It never has been. The Iraq war was a war of choice; we can choose to leave. We should.