Remember how people claimed we could save money by retreating from Iraq?  Barack Obama calculated that savings into his proposed economic plans during the presidential campaign as did Congressional Democrats during budget battles over the last two years.  However, it appears no one actually asked the Pentagon whether a withdrawal would produce short-term savings until now — and the answer is a resounding no:

The removal of about 140,000 U.S. troops from Iraq by the end of 2011 will be a “massive and expensive effort” that is likely to increase rather than lower Iraq-related expenditures during the withdrawal and for several years after its completion, government investigators said in a report released yesterday.

“Although reducing troops would appear to lower costs,” the Government Accountability Office said, withdrawals from previous conflicts have shown that costs more often rise in the near term. The price of equipment repairs and replacements, along with closing or turning over 283 U.S. military installations in Iraq, “will likely be significant,” the GAO reported.

Even the smallest facilities, with 16 to 200 combat troops, will take up to two months to close, the report said. Several dozen large installations — such as Balad Air Base, with 24,000 inhabitants — are likely to take 18 months or more.

Earlier, Obama talked about a 19-month timetable for withdrawal.  If he plans to meet that, he’ll have to start working on Balad and other large facilities by next week.  Otherwise, it will take longer than 19 months, and the costs associated with withdrawal will grow for years.

That’s not exactly a reason to stay, either, but then again, the cost of the mission is a weak reason to depart, too.  The better question would be how to ensure that we succeed in stabilizing and supporting the nascent democracy in Iraq.  The Post outlines many problems still facing the Iraqis, from basic human needs (sewage, water, electricity) to political standoffs over oil revenue and disarming militias.  The US military can play a role in both, but only if the Iraqis can rely on our presence while we shift out of combat roles to engineering, logistical, and training roles.  The Iraqis have to want us to remain for those efforts, and at least for the moment, they do.

A collapse in Iraq will cost America dearly, much more than the phantom savings of withdrawal even when we didn’t know they were illusory.  A failed Iraq will encourage Iranian aggression, foment radicalism and terrorism, and could start a war between Kurds and Turks if the former decides to declare complete independence in the absence of a cohesive Iraq.  Since it won’t save us money in the short- or mid-term, we may as well stay and finish the job.