The lefties won’t be happy, busts that campaign promise to do it within 16 months.

“WASHINGTON — President Obama won crucial backing on Thursday for his Iraq military withdrawal plan from leading Congressional Republicans, including Senator John McCain, the party’s presidential nominee, who spent much of last year debating the war with Mr. Obama.

As the president prepared to fly to Camp Lejeune, N.C., on Friday to announce that he would pull combat forces out by August 2010 while leaving behind a residual force of 35,000 to 50,000 troops, he reassured Congressional leaders from both parties that his plan would not jeopardize hard-won stability in Iraq.

But Republicans emerged from a meeting Thursday evening more supportive than several leading Democrats, who complained earlier in the day that the president was still leaving behind too many American forces.

Mr. McCain said during the private White House meeting that he thought the withdrawal plan was thoughtful and well prepared, according to several people who were in the room. His spokeswoman, Brooke Buchanan, confirmed by e-mail on Thursday night that Mr. McCain is “supportive of the plan.”

The convergence of Mr. Obama and Mr. McCain on Iraq would have seemed highly improbable just a few months ago, when they clashed harshly on the future of the American mission there. Mr. McCain accused Mr. Obama of being naïve and opposed his withdrawal plans. At one point, Mr. McCain said Mr. Obama “would rather lose a war than lose a campaign.”

Even since the inauguration, Mr. McCain, who represents Arizona, has remained a tough opponent of Mr. Obama, at least on economic matters. But the two have come to a common ground of sorts on Iraq, the issue that once defined their rivalry.

Mr. McCain’s views were echoed by other Republicans briefed in the State Dining Room by Mr. Obama, Defense Secretary Robert M. Gates and Adm. Mike Mullen, chairman of the Joint Chiefs of Staff. The Obama team told two dozen lawmakers from both parties that at least 90,000 of the 142,000 troops in Iraq would be withdrawn by August 2010 — 19 months after the president’s inauguration, or three months longer than the time frame he had outlined as a candidate.

Most withdrawals will take place next year to allow commanders to keep as many forces as possible through parliamentary elections in December. Mr. Gates and Admiral Mullen told the lawmakers that Gen. David H. Petraeus, the Middle East commander, and Gen. Ray Odierno, the Iraq commander, were comfortable with the plan, according to people in the room.

Representative John M. McHugh of New York, the ranking Republican on the House Armed Services Committee, said Mr. Obama had reassured him that he would revisit his plan if circumstances changed.”

No doubt this wasn’t Obama’s decision, the plan had been in operation under Bush with pretty much the same game plan. With Iraq settling down troops will be needed elsewhere – like Afghanistan likely sooner than later. Yet as I’ve said on many occasions there will be a significant troop presence in Iraq – about 30-40,000 troops for some time to come.

The point is that we have troops in the region where they give us a strategic advantage if Iran decides to try us with a nuclear weapons procurement.

With that in mind I see this “plan” undergoing several more changes between now and next summer.