GOP presidential candidates were quick to criticize President Obama 's decision to withdraw all U.S. troops from Iraq by the end of the year, as The Post’s Karen DeYoung pointed out in an online story Friday, which appeared in print Saturday. But the headline on the story was a bit misleading, as too was the story.

The online headline read: “GOP presidential field unified in opposition to Iraq withdrawal.” The print headline read “GOP candidates united against Iraq withdrawal.”

It is true that most of the presidential candidates — Mitt Romney, Rick Perry, Michele Bachmann and Jon Huntsman — criticized Obama on Friday, after the president announced that the troops would be coming home.

But Rep. Ron Paul (R-Tex.) and former New Mexico governor Gary Johnson have said for some time that the troops need to return from Iraq, and quickly. Johnson tweeted on Friday, “Troops out of Iraq by the holidays — Good news, but LONG overdue.”

Paul did not put out a specific statement that day, but he voted against the Iraq war resolution in Congress and has long advocated ending the wars in Iraq and Afghanistan.

So it’s not true that the GOP field was unified, nor did they all speak with one voice, as the Post’s lead stated: “Despite their inability to agree on the economy or much else, Republican presidential candidates spoke with one voice in reaction to President Obama’s announcement of a full U.S. withdrawal from Iraq this year. They were against it.”

But it’s also useful to note that DeYoung, The Post’s senior national security correspondent, does not cover presidential politics every day and that she contributed to three other stories that day.

She assisted with a story on Libyan dictator Moammar Gaddafi’s death and the aftermath in that country, and on two stories about Secretary of State Hillary Rodham Clinton’s trip to Pakistan, one on the message being given to Pakistan’s leaders and the other on U.S. contacts with the Haqqani network, which has been behind attacks in Afghanistan.

She wrote the GOP story at 6:30 p.m. after contributing to the other three, and she didn’t see the headline on the story before she left work.

“When I wrote that the candidates spoke with ‘one voice,’ I was referring to those who had issued public statements that afternoon in response to President Obama’s announcement,” DeYoung said.

“I also mentioned Herman Cain, who had spoken specifically about the timing of the Iraq withdrawal two days earlier. I don’t know what time Gov. Johnson tweeted on the subject; I did not see it but I should have. I was also well aware of Rep. Paul’s position advocating withdrawals from Iraq and Afghanistan; I should have included this, regardless of whether he spoke Friday in specific response to the Obama announcement.

“Overall, it was a very busy day in which I was involved in stories on Iraq, Libya and Pakistan. But that’s no excuse; the story could and should have been better and made clear that it did not reflect the entire field of candidates. On the headline — reporters don’t write them, and they are often composed long after the reporters are gone for the night. I thought the headline was misleading and went further than the story did.”

Many, if not most, Post reporters are working like DeYoung — writing more than one story, contributing to others, contributing to blogs. It makes for a crammed day, and sometimes mistakes.

It’s also useful to note that Obama is carrying out the agreement that President George W. Bush negotiated with Iraq in 2008, to withdraw all troops by the end of 2011. Some military and foreign policy experts have urged Obama to leave a small force of U.S. troops in Iraq to continue training Iraqis and to act as a stabilizing force.