Is the "red line" on Syria's chemical weapons blurring?

A post office worker shows to an Israeli child how to wear a gas mask at a gas mask kit distribution station in a mall January 31, 2013, in Pisgat Ze'ev, East Jerusalem, Israel. / Getty Images

London President Barack Obama said the U.S. was still investigating claims that chemical weapons were used in Syria to determine if a "red line" had been crossed, reiterating that any such use would represent a "game-changer" in terms of U.S. action toward the Assad regime.

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Obama: If Syria used chemical weapons, it's a "game changer"

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Rep. Rogers on Syria: "Probability," "evidence" of chemical weapons use

But Mr. Obama was clear that the facts of Tuesday's alleged chemical attack - for which both the rebels and the regime traded blame - had yet to be conclusively established, including whether it took place at all, despite some escalating rhetoric from within the U.S. and Israel.

Rep. Mike Rogers, R-Mich., chairman of the House Intelligence Committee, told "CBS This Morning" on Wednesday that there was a "high probability that a chemical agent was used in Aleppo."

"There has been some forensic evidence that at least small quantities may have been used in the past," said Rogers.

Israeli cabinet minister Yuval Steinitz echoed that sentiment Wednesday morning, calling it "apparently clear" that chemical weapons were recently used in Syria, just as Mr. Obama was due to touch down in Tel Aviv.

But if Rogers had information on forensic evidence, he didn't elaborate on it.

Others have been more cautious with their characterizations of Tuesday's incident. U.S. Ambassador to Syria Robert Ford told a House panel that the U.S. "no evidence to substantiate the reports that chemical weapons were used yesterday," And Rep. Dutch Ruppersberger, D-Md., who is the top-ranking Democrat on the House Intelligence Committee and has been briefed on the matter, wouldn't go as far as Rogers' "high probability" comment, saying only that he was "very concerned" about the reports.

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The devil is in the details

CBSNews.com has spoken to two leading experts in chemical and biological weapons and warfare, and the clear consensus is that no chemical weapons have been used inside Syria.

"I am extremely skeptical that this (Aleppo strike) was a chemical warfare incident," said Jean Pascal Zanders, an expert in chemical and biological warfare with the European Union Institute for Security Studies.

This satellite image shows one of Syria's two dozen chemical weapons bases.

/ CBS News/DigitalGlobe

Zanders said that images of victims in local hospitals and their descriptions of what they experienced left him with little doubt.

"The descriptions (of symptoms) would be totally, totally different to what we've been reading" if one of Syria's known chemical agents had been dispersed.

Syria is known to have significant stockpiles of Sarin gas, mustard gas and a variety of other military-grade agents, which attack the human respiratory and nervous systems.

There were many claims that a chlorine odor was present after the explosion in Khan al-Assal, and that victims suffered acute respiratory problems. There were even claims that some died of asphyxiation, but there was no evidence of dead bodies. In all, Zanders said evidence of a chemical weapons attack was very weak.

Rogers, however, was careful not to use the term "chemical weapons" on Wednesday. He said "chemical agents."

While Rogers would not elaborate on what he believes the Assad regime may have used against the rebels, Syria expert Salman Shaikh, director of the Brookings Institution's Doha Center, suggested to CBSNews.com on Wednesday that the government has been "experimenting with various compounds and mixtures to see how they could use these (chemical agents) in a localized fashion."

Shaikh said his sources, who travel to and from Damascus and maintain contact with both current and former regime officials, are certain that Assad's regime has tried out less lethal, less widely dispersed compounds for months.

His contacts, "believe they (the regime) could produce mixtures that would produce harm, but not on a massive level ... and could be deployed within, say, a one-square-mile area," to target rebel holdouts in a particular area.

While Shaikh suggested that the less-lethal compounds could include weapons derived from Syria's known stockpiles of sarin gas and other agents, a far less sinister substance may be at the root of the current chemical weapons rhetoric: pesticide.

Hamish de Bretton-Gordon, an expert in chemical and biological weapons and the head of U.K. consultancy SecureBio, told CBSNews.com on Wednesday that the culprit could well be organic phosphates, which he described as "the basis in all chemical weapons."

Organic phosphates, explains Bretton-Gordon, "are a key part of pesticide, but it is the basis for nerve agents," and there is "a lot in the country."

He said using organic phosphates as a weapon is, "not complicated: You get a bag of pesticide and you blow it up, and there is going to be fallout from the organic phosphate."

Even one bag of pesticide could be sufficient to cause symptoms, which he described as similar too, but "not nearly so widespread as a chemical weapon," according to Bretton-Gordon. Those symptoms generally begin with pinpoint pupils, disorientation, dizziness and salivation; with a higher dose, those symptoms include collapse, difficulty breathing, convulsions, loss of control of bodily functions, and eventually, death.

Bretton-Gordon notes, however, that to cause mass fatalities, "you would need a pretty good whack of organic phosphates."

A Washington D.C.-based Syrian opposition group claimed Wednesday that rebels in Aleppo had confirmed the missile which struck Khan al-Assal on Tuesday was tipped with Echothiophate, which it called "a chemical warfare agent" found in insecticides.

So where is the red line?

Rogers asserted on CTM Wednesday that the U.S. has the military "ability to remove" Syrian President Bashar Assad's capabilities to actually use his chemical weapons without putting soldiers on the ground.

"I doubt it very much," responded Zanders. "Sure, they can hit the storage sites, but if you hit the storage sites you get the uncontrolled release of agent. There is no way you can hit the storage sites without producing a cloud that is going to kill indiscriminately in the area. It would absolutely backfire if the Americans were to do this."

"One really has to be careful that ratcheting up the rhetoric does not serve the purpose of a military intervention," Zanders said. "We've seen it on the eve of the invasion of Iraq. These types of allegations were being made."

Rogers seemed to suggest Wednesday that it may be a short leap from "agent" to "weapon."

An image from Syrian state television shows a man reportedly being treated in an Aleppo province hospital after an alleged chemical weapons attack, March 19, 2013.

/ Syrian State TV

"If we're ever going to have a diplomatic solution, where this regime doesn't get to the point where it uses mass quantities of chemical weapons, we've got to rebuild our credibility," Rogers told CTM's Charlie Rose. "One way to do that is to remove their capability to use chemical weapons on civilians."

The question then becomes, does the use of organic phosphate or other chemical "agents" constitute a crossing of the Obama administration's red line? Would proof that the regime is using such compounds against rebels -- even in populated areas -- bring a preemptive strike that could draw the U.S. into a war in the Middle East?

President Obama landed Wednesday in Israel for a four day "listening" tour in the region. He will likely be grappling, as he listens, with just how clear the red line he painted months ago remains today.

[littleredtop]

Obama wants to enter this civil war so that he'll be a shoe-in for his third and possibly fourth term. I say let those people sort out their differences without outside intervention.

[kevcl6750]

With Neville Chamberlain the 2nd in charge what did you expect ! Next thing you know they will be blaming the sequester for the Bengazi disaster retro actively . I would not put any line of BS past this group !

[excop1949]

Is the "red line" on Syria's chemical weapons blurring?

IF IT IS, IT'S BECAUSE OBAMA KEEPS MOVING IT...

[signseeker1717]

The "blurring" is the fact that there continue to be conflicting reports, and no definitive proof chemical weapons are being used.

As long as you stop at headlines and never bother to read the articles, you'll never get a clear picture of ANY "line".

[antoniof123]

I am asking everyone sign any petition not to let America get involved any deeper. We can't afford this if the Republicans want to go to war, let them pay for it.

Any registered Republicans has to pay extra and only their kids go.

Pretty simple most people were tricked by the Republican into Iraq so now let the guilty pay for it with their own I don't want to pay for it.

[robert1129]

Would Rep. Rogers, McCain, Et Al, have the guts now to sponsor reinstatement of the draft and sponsor an increased war tax? Lessons we should have learned from Iraq are do not use the same troops over and over again and spare most of the USA from the type of sacrifices required, do not conduct wars on the cuff and be prepared to endure the hostilities generated from another war. Are these guys ready to advocate that? Not on your life and fat chance.

[falseemail58]

Chemical weapons ???? gimme a break - Potential, probable, possibly in the past *** - when are you Americans going to start to question your security sources

Just like all those weapons of mass destruction you NEVER found

More Lies, agenda's and murder - SHUT the **** up U.S.A - how about the stats in Iraq - less than 5000 US soldiers dead compared to most estimates that anywhere between 100-150,000 dead iraq's 80% civilian - there is now over 800,000 orphans !!! sound like a fair fight ? still think Iraq will be in a better state when you leave ? It will take Iraq generations to fully recover

And now possibly joining Israel - the home of the never ending wars ? Unbelievable - is that what you want ?

You are smart people, you have led the world in progress since WWII - you should ALL be proud of your influence on world progress. You are an amazing people BUT really it's time to back off for a while

Fix up your home front, trillion $$ national debt, lunatic gunman, increased poverty, unbelievable crime rate, failing economy and on and on and on

c'mon residents of the USA - you gotta stop these weirdo's in the CIA or who ever they are that advises your Presidents that dabbling and meddling in other countries problems aint your business. For me, As an ally - this means more Australians join your dumb ass wars. sure we only lost 2 citizens - but most everyone here is embarrassed that we went to Iraq with you - it's a bloody awful business

Fix yourselves before you get on the white horse - we (rest of the world) simply need a break

We are exhausted also

[dylan_89]

how about we just let the UN and everyone else deal with this one while we work on the problems we already have.

[signseeker1717]

They do - it's called SANCTIONS. NATO and the EU have them too. But that won't stop people from talking about the issue.

The danger is this: "One really has to be careful that ratcheting up the rhetoric does not serve the purpose of a military intervention".

[TooScruffy]

For this administration to "still be investigating", means nothing will happen. They are "still investigating" Fast and Furious and the Benghazi attack. Total impotence.

[silvereagle2718]

It means nothing of the sort.

I would be disappointed if Mr. Obama started a war lightly. During his first term, there have been revolutions resulting in the overthrow of the governments of at least two UN member states (Egypt and Libya). Was Tunisia a third?

It is not clear that a precedent of overthrowing governments is desirable. Letting Syria burn sends the message that the Security Council will not be led by the nose.

That having been said, he, Syria, this country, and the rest of the world have to live with whatever decision he makes.

Heads may yet roll over fast and furious. I'll believe it when I see it. It is not clear (to me) that (American) heads should roll over the Benghazi attack.

[signseeker1717]

Congress ALREADY investigated Fast and Furious (a program that started under Bush, BTW) and determined that Holder has nothing to so with it. The program was terminated. Congress ALSO held hearings on Benghazi (didn't you watch?), a Report of recommendations was issued to make sure it wouldn't happen again, and all recommendations were enacted by the State Department.

Both have been dealt with, and are OVER. What more do you want?