President Obama, who rode his opposition to the Iraq War straight into the White House, isn't so eager to talk about the conflict there anymore.

The chaos just outside Baghdad has the potential to puncture Obama's carefully crafted narrative, even more than the civil war in Syria or Russian aggression in Ukraine, because his political image is more closely linked to Iraq than any foreign policy issue.

The capture of Mosul and Tikrit by militants tied to the Islamic State of Iraq and Syria has once again called into question whether Obama is quick enough to deploy U.S. resources that could deter instability abroad — a point that even some of the president's allies acknowledged.

“This is a huge deal,” a former Obama counterterrorism adviser told the Washington Examiner. “You can’t really overstate how big Iraq is when it comes to perceptions of the president. His arguments aren’t nearly as persuasive if the entire country is in shambles.”

Just this week, Obama's aides cited his handling of Iraq as among his greatest foreign policy accomplishments. In the 2012 presidential debates, Obama mocked Republican rival Mitt Romney for even suggesting his administration should have left more U.S. troops behind in Iraq. And in 2008, then-Sen. Obama used his disapproval of the Iraq War to win over progressives wary of frontrunner Hillary Clinton.

With insurgents now marching toward Baghdad, the GOP has pounced on the instability as proof of Obama's naivety about a region spiraling out of control.

The president on Thursday said he was not ruling out the possibility of airstrikes in Iraq, a sign of just how dramatically his calculations there have shifted. The Iraqi government has been pushing for some form of air support from the Obama administration with little success.

And though Obama -- and Republicans for that matter -- are opposed to putting troops on the ground in Iraq, the president again faces the uncomfortable question of whether to seek congressional approval for military action in the Middle East.

Obama’s dilemma comes just weeks after he delivered a major foreign policy address at West Point in which he said his main goal was to avoid messy foreign entanglements whenever possible — a theme he tried to strike again Thursday.

“We’re not going to be able to be everywhere all the time, but what we can do is to make sure that we are consistently helping to finance, train, advise military forces with partner countries, including Iraq, that have the capacity to maintain their own security,” he insisted.

However, insurgents have seized power with virtually no resistance from U.S.-trained Iraqi military forces.

“It appears to me that the chickens are coming home to roost for the president's policy of not leaving anybody there to be a stabilizing force,” said Sen. Roy Blunt, R-Mo., a member of the Senate Armed Services Committee. “Some Iraqi troops have gone to work with their uniforms on with civilian clothes under their uniforms. That's a bad sign.”

Sen. John McCain, R-Ariz., said the situation was so dire that the president should replace his national security team. Speaker John Boehner, R-Ohio, accused Obama of “taking a nap” while conditions worsened.

While the White House has repeatedly touted Obama's decision to end the Iraq War, the administration now is opting to avoid amplifying the messy conditions on the ground.

Republican staffers were quick to highlight portions of a March 2012 speech in which Tony Blinken, now Obama’s deputy national security adviser, claimed Iraq was “less violent, more democratic and more prosperous” than “at any time in recent history.”

However, some analysts said Republicans would be mistaken to use the escalating violence in Iraq for political gain.

“It’s hard to claim what is happening is Iraq is a success. That would be absurd,” said Christopher Preble, vice president for defense and foreign policy studies at the libertarian Cato Institute, dismissing the White House’s reasoning. “But it’s not incumbent upon Obama to prove that this was a success. His argument was that it would be worse if we stayed. I don’t see any evidence that the American people are anxious to go back into Iraq.”

Polls have repeatedly shown that ending the Iraq War was one of Obama's most popular actions. But some cautioned that if Iraq becomes another Syria, the president would be left with few concrete successes abroad.

“That’s the nightmare for the White House,” said the former Obama adviser. “There’s no good way to spin that.”