Journalists have been told by the administration to 'place more credibility in on-the-record statements' – but that hasn't stopped the White House leaking information when it suits

Just as the White House unveiled its dossier of evidence of chemical weapons attacks in Syria on Friday, two senior administration officials were giving a telephone briefing to the media. They were authorised by the administration to attest to the reliability of intelligence suggesting the attacks were carried out by Syria – but only on the condition of anonymity.

Exactly 24 hours earlier, the White House deputy spokesman Josh Earnest had discouraged reporters from trusting anonymous administration officials, saying they should "place more credibility in on-the-record statements".

The shadow of the Iraq war looms large over the Syria crisis, not just for the White House, but for journalists too. Parts of the US media were perceived to have failed to sufficiently challenge the evidence for the presence of weapons of mass destruction in Iraq, in the run-up to the invasion in 2003. This time around, there's a discernible air of scepticism.

The Obama administration, on the other hand, seems to be happy to leak information when it suits it and condemn leaks when it doesn't.

Not all briefings on the intelligence case for action in Syria have been off the record. The secretary of state, John Kerry, has twice made public statements about Syria, although he opted not to take questions. The secretary of defence, Chuck Hagel, and the president have spoken briefly on the topic when pressed in front of TV cameras. But they have not said explicitly that the US is launching military action, and didn't even admit it was being contemplated until Wednesday.

Instead, the mood music that led pretty much every media outlet to say confidently that the US was on the brink of military action came courtesy of an ensemble of unofficial sources.

In what had all the appearances of a sanctioned chorus of leaks, senior administration officials have discussed the administration's readiness for action and the basis for launching air strikes against Syria with a variety of outlets. While it's probable that not all the unsourced stories about Syria were part of a briefing campaign, it has very much looked like an orchestrated spin, and the administration's apparent policy of serially leaking classified information has attracted criticism from all corners.

The Republican senator John McCain worries that the Syrian regime has been given a "crazy" advantage by reports that reveal the timing, nature and even probable location of sites that will be attacked by cruise missiles. Others have alleged hypocrisy, pointing out that the Obama administration has waged an unprecedented war on unsanctioned leakers, most notably Chelsea Manning and Edward Snowden.

It all came to a head in the White House briefing room on Thursday, when Earnest was pressed on an AP report that cited "multiple US officials" who all used the same phrase to describe the intelligence assessment on the Syrian attack: "Not a slam dunk". Reuters had a similar story, quoting US national security officials, saying there was "no smoking gun" that Bashar al-Assad, the Syrian president, had personally ordered the attack.

For once, the anonymous stories had not gone quite the way the administration had wanted them. The AP story was the result of a demand by its investigations editor earlier in the week that hard questions be asked of intelligence sources.

Earnest tried to bat away questions on the subject. "You've got a handful of anonymous individuals who are quoted in that story," he said.

"Do you disagree with it?" a reporter asked.

When Earnest knocked back another question seconds later, because it was based on anonymous sources, an incredulous reporter shouted out: "Josh, you guys talk to us anonymously all the time and expect us to believe those credible statements."

"I'm just saying that anonymous sources …" Earnest began.

"But you talk to us anonymously all the time!" said another journalist.

Could Earnest have been one of those anonymous sources he was now suggesting were unreliable? If not, he is certain to have provided others like them, as he admitted. "What you also say to me, on a regular basis when I and others speak anonymously to you, is that you place more credibility in on-the-record statements," Earnest said, with what looked like a straight face. "So that's all I'm directing you to right now."