Not just once, either. Repeatedly. That makes not one but two close U.S. allies whispering that Assad’s gone and done the thing that the leader of the free world said he Must Not Do.

It’s intervention time.

Israel’s senior military intelligence analyst said Tuesday there was evidence the Syrian government had repeatedly used chemical weapons in the last month, and he criticized the international community for failing to respond, intensifying pressure on the Obama administration to intervene.

“The regime has increasingly used chemical weapons,” said Brig. Gen. Itai Brun, research commander in the intelligence directorate of the Israeli Defense Forces, echoing assertions made by Britain and France. “The very fact that they have used chemical weapons without any appropriate reaction,” he added, “is a very worrying development, because it might signal that this is legitimate.”…

The Syrian attacks killed “a couple of dozens,” the military official said, in what Israel judged as “a test” by President Bashar al-Assad of the international community’s response. He said the government had deployed chemicals a handful of times since, but that details of those attacks were sketchier.

“Their fear of using it is much lower than before using it,” the official said. “If somebody would take any reaction, maybe it would deter them from using it again.”

Netanyahu allegedly told John Kerry he couldn’t confirm the claim (which is odd, if Israeli military personnel are talking publicly about it), but the IDF’s intelligence arm thinks the weapon of choice was sarin based in part on photos of the victims foaming at the mouth with shrunken pupils. How they can be confident about that, though, I’m not sure: This Times piece is a nice quick tour of the difficulties of confirming that chemical WMD were used if you don’t have access to the scene or the victims and there aren’t lots and lots of bodies to prove that something unusual occurred. British intelligence allegedly got hold of a soil sample from the site of one attack that was smuggled out of the country, but how do you trust the provenance? Could be the rebels cooked up the sample somehow to try to engineer western intervention, or maybe they overran one of Assad’s chemical facilities and scraped it off there. (On the other hand, check out this photo of dead animals, all apparently killed bloodlessly near the site of one attack.) It’s surreal that U.S. entry into the war may hinge on sarin attacks that have killed “dozens” when conventional warfare killed more than 500 Syrians in one Damascus suburb over the past week alone, but there you go. That’s the “red line” calculus at work, to maintain the WMD taboo for other bad actors.

Chuck Hagel dropped a big hint last week that the White House might be preparing for action. Here’s another little nudge from Kerry:

U.S. Secretary of State John Kerry on Tuesday urged NATO to prepare for the possible use of chemical weapons by Syria and called for alliance members to boost their assistance to the Syrian opposition.

Attending his first meeting of the alliance’s governing body, the North Atlantic Council, as America’s top diplomat, Kerry said contingency plans should be put in place to guard against the threat of a chemical weapons strike. NATO ally Turkey borders Syria and would be most at-risk from such an attack. NATO has already deployed Patriot missile batteries in Turkey.

“Planning regarding Syria, such as what (NATO) has already done, is an appropriate undertaking for the alliance,” Kerry told NATO foreign ministers. “We should also carefully and collectively consider how NATO is prepared to respond to protect its members from a Syrian threat, including any potential chemical weapons threat.”

I’m interested in the gamesmanship here by having a top Israeli military intel official go public with this while Obama’s trying to decide what to do or whether to acknowledge that a chemical attack happened at all. Is that Netanyahu playing an angle, formally denying any knowledge himself while getting the IDF to twist O’s arm by announcing this publicly? Or is this being done in concert with the White House, with O encouraging the Israelis to release the info as a test of U.S. public opinion? If there’s a big Do Something outcry, then he may have to act; if not (and there won’t be), then he can keep looking the other way for awhile. The problem with that theory, though, is that it assumes the public won’t blame the White House later if O refuses to act now and then there’s a mass-casualty attack in Syria involving sarin or something similarly foul. Just yesterday, Hagel insisted that WMD use in Syria would be a “game changer” (Obama has used those words himself), but what kind of game is being played here?

Speaking of which, here’s ABC pressing Carney today on whether Obama still considers chemical weapons in Syria a “game changer.” He’s … noncommittal.