Reading glasses perched high on his bald head, Brig. Gen. Itai Brun delivered an informative lecture at a conference organized by the Institute for National Security Studies on Tuesday. Unusually informative.

The IDF’s top intelligence analyst spoke about the international community and the way its leaders are “sucked” into the Middle East maelstrom against their will. He spoke about the changing nature of the global jihad now that some of its more powerful elements have taken root along Israel’s borders. He mentioned the rise of Islamist ideology — its surprising practicality — and the widening role of Qatar in the Sunni camp.

And then, after speaking too about Iran and the challenges of intelligence work in the age of the Arab Spring, he dropped his bombshell: “To the best of our professional understanding, the regime has used lethal chemical weapons,” he said of President Bashar Assad’s Syria, noting that the IDF believed the toxic element was Sarin, a nerve agent far more deadly than cyanide, and that it had been used on more than one occasion, including in a specific attack on March 19.

The US, both before and after Brun’s statement, has gone out of its way to avoid making that kind of declaration. “We are looking for conclusive evidence, if it exists, if there was use of chemical weapons,” Jay Carney, the White House press secretary, said later Tuesday.

In Brussels, Secretary of State John Kerry rushed to declare that Prime Minister Benjamin Netanyahu was “not in a position to confirm” Brun’s assessment.

In Cairo on Wednesday, Defense Secretary Chuck Hagel said he was caught by surprise by the expert IDF analyst’s definitive statement. “They did not give me that assessment,” he said. “I guess it was not complete.”

Both President Barack Obama and Hagel have said that the use of chemical weapons in Syria – weapons of mass destruction – would constitute a game changer, a crossing of a red line that would demand American intervention. This is a step that the US administration and the American public, as the armed forces withdraw from a decade of war in the Middle East, seem disinclined to favor.

Why, then, did Brun make the IDF’s determination public? US and Israeli intelligence officials meet all the time. If he had information to convey – if he was just being helpful – then he could have passed the evidence he possessed in an appropriately clandestine manner. Why contradict the official US position, and why do so while the secretary of defense is in the country? Hagel, after all, a) holds firm anti-interventionist positions; b) has just delivered Israel a whopping arms deal, and c) had confirmed just the day before that chemical weapons in Syria would be “a game changer.”

Brun, in his presentation on Tuesday, quoted Harvard professor Joseph Nye and said that in the intelligence world he is faced with two sorts of obstacles – secrets and mysteries. The former can be stolen; the latter are unknown even to those who hold the secrets. So how to classify Brun’s own revelation at the conference? Was he secretly trying to goad the US into action or was he, unbeknownst even to himself, altering the course of events in trying to present a compelling lecture?

The US, as Hagel intimated, has every right to rely solely on its own intelligence, certainly after the WMD debacle in Iraq. Israeli security officials, though, seem certain that Brun’s information is rock solid.

Brun showed a photo of a child with narrowed pupils and foam coming out of his mouth. Both of these are indicative of a nerve agent, he said. But it’s safe to say he did not, in the age of Muhammad al-Dura, rely solely on the evidence provided by a picture. “From my 20 years of working at the research and analysis division (of military intelligence) I can assure you he would not go public based only on that,” said Dr. Dany Shoham, a senior research fellow at the Begin Sadat Center for Strategic Studies and an expert on Syrian chemical weapons.

Soil samples, Shoham said, which have reportedly been obtained by Britain and France, could provide somewhere between 60-100 percent indication of a nerve agent. A post mortem examination, he added, “could be very, very helpful.”

The death toll in the March 19 attacks near Damascus and Aleppo make clear that if chemical weapons were in fact used, the usage was, in the military parlance, tactical.  “The deployment was tactical, local, delivered by artillery shells,” Shoham said. A wide-impact method of delivery, by plane or on the tip of a missile, would result in a greater volatility and toxicity and a much greater death toll.

“This could be one of the differences between the US and Israel’s view,” said Giora Eiland, a former general and ex-national security adviser to the prime minister. “The American red line might have referred to a massive usage, as delivered by a plane or a missile.”

This kind of ambiguity, incidentally, explains why red lines – unless they trigger a reaction under even the most unfavorable circumstances – can be more of a nuisance than an effective tool. Iran and Syria cannot be corralled into compliance by the marking of a red line. Instead, what seems to be emerging, both where Iran and Syria are concerned, is that the American red line is something that can be crossed but not trampled. Assad has 1,000 tons of chemical weapons. He could carry out a holocaust. But then, presumably, the US and NATO would act. Instead, according to Brun, Assad has made limited yet repeated use of the horrific weapon.

A similar dynamic has taken hold in Iran. Maj. Gen. (res) Amos Yadlin, the former head of military intelligence and current director of the INSS, said at the same conference Tuesday that Iran, which has been converting its 20-percent enriched uranium into an oxide form, “has no problem at all” converting it back into a gas. “Within a week it could be converted back to nuclear material for a bomb,” Yadlin noted.

Brun, the top intelligence analyst in the IDF, does not step into daylight and speak off the cuff. Nor does he speak without the authorization of, at very least, the head of military intelligence. Publicly, authoritatively, declaring that the line has been crossed could reasonably be interpreted as a push in the direction of US action on Syrian soil.

Eiland dismissed that theory. “I don’t think Israel has any such interest,” he said.

Eiland characterized Israel as “very thrifty” in determining its interests. An interest, he added, is something for which you are willing to sacrifice. Israel would not likely be willing to harm its ties with the US in order to save Syrian rebels from Assad’s brutality. Certainly not with the United States recuperating from two wars in the Middle East as a third, in Iran, a far graver threat, flickered on the horizon. What’s more, sounding the whistle and serving as the trigger for NATO or US action in Syria would put Israel in a vulnerable position, Eiland said.

Shoham agreed. Dragging the US into Syria would do little for US-Israel relations and even less in terms of building a credible US military option in Iran.

Instead, difficult as it is to believe, therefore, Brun may just have stumbled into his incendiary statement. Security experts, Eiland said, sometimes face a dilemma when asked to speak in public. “You don’t want to sound banal or boring, and you don’t want to give up secrets.”

Any professional intelligence officer, Eiland said, would first and foremost worry about the dangers of making a statement that might burn a source or an agent. “You don’t want to say something that could be traced back to a certain individual,” he said. “That would be a key consideration for him.”

As for Brun, a top notch officer by all accounts, putting his foot in his mouth and creating the sort of maelstrom that forces Kerry and Netanyahu to tie themselves up in knots so as to appear to agree, well, that, Eiland indicated, was entirely possible.