Syrian Chemical Weapons: What We Need To Know (Cheryl Rofer)

We’re pleased to present this guest-post by former Los Alamos chemist Cheryl Rofer, originally posted at NuclearDiner. It’s a level-headed look at the news circulating that the White House has said Syria’s Assad has used chemical weapons. Steve H.

Secretary of Defense Chuck Hagel said Thursday in the United Arab Emirates that the United States has some evidence of sarin use in Syria. The administration’s position is laid out in a letter from Miguel Rodriguez, director of the White House Office of Legislative Affairs, to Senator Carl Levin.

As usual in sensitive government communications, it’s worth looking at the letter very carefully.

Our intelligence community does assess with varying degrees of confidence that the Syrian regime has used chemical weapons on a small scale in Syria, specifically the chemical agent sarin. This assessment is based in part on physiological samples.

Our intelligence community does assess with varying degrees of confidence   This probably means that different intelligence agencies have different assessments and that there is no consensus. It would be useful to know which agencies provided what assessment. In the case of Saddam Hussein’s aluminum tubes, the Department of Energy, which has the people who know how to make centrifuges, said that the aluminum tubes couldn’t be used for centrifuges.

that the Syrian regime has used chemical weapons    A lot of evidence is needed to support this statement. If there is evidence of exposure to sarin, it could come from insurgents accessing chemical weapons and exposing themselves or using the chemical weapons. The letter goes on with this support:

We do believe that any use of chemical weapons in Syria would likely have originated with the Assad regime. Thus far, we believe that the Assad regime maintains custody of these weapons, and has demonstrated a willingness to escalate its horrific use of violence against the Syrian people.

on a small scale in Syria    This probably refers to one or more of the incidents reported last year. It is a small scale indeed, perhaps less than a standard military shell. So how was it dispersed? Or do very small munitions exist, the size, say, of tear gas canisters? Why would Assad use small amounts of sarin when Obama has said it’s a red line? Others are wondering about this too.

This assessment is based in part on physiological samples.    Is the other evidence what the second excerpt I’ve quoted is based on? Supposedly other countries have analyzed soil samples; is that more of the evidence? The videos from those incidents included? If so, have they been verified?

Wired says that the physiological samples were blood from victims. Anonymous “intelligence community” sources again. How certain was that person’s agency of the assessment? I’d guess that it’s one of the ones that is more rather than less convinced. Leaking is how to get your agency’s viewpoint out around the White House statement.

For example, the chain of custody is not clear, so we cannot confirm how the exposure occurred and under what conditions.

Chain of custody means assurance that the samples are what they are said to be. The sample is taken and sealed in a tamper-proof manner. The sample-taker signs off on a paper that accompanies the sample. Each person to whom the sample is transferred signs off on that paper. The reason is that samples can be faked from the start or adulterated somewhere along the line. Given the chaos in Syria, however, I doubt that a credible chain of custody can be produced, even if a piece of paper with signatures exists. You have to be able to believe all the people who signed off.

A quick Google search suggests that gas chromatography is the method of choice for analyzing sarin in blood. There seem to be at least two methods, both fairly involved. The more direct method is affected by the amount of time between exposure and analysis. We don’t know what that was in this case. I find the writeup of the other method confusing, but the paper lays out exactly how a sample could be faked. All that would be needed would be a very small amount of sarin, which might be, say, stolen from a laboratory, and someone’s (anyone’s) blood. Was the blood tested to show it was human?

The method of analysis is important. I am guessing that for such a public statement a method like the two I linked in the previous paragraph was used, but there are field methods that are not as exacting and may give false positives. So apparently the white powder in those envelopes tested positive for ricin, but it was not the pure material, but rather ground-up castor beans, which contain ricin but are not as dangerous.

Chain of custody is required for police evidence and for the environmental investigations that I have supervised. I would hope that it would be required for going to war. Presumably that is the reason the letter goes on to say

However, precisely because the President takes this issue so seriously, we have an obligation to fully investigate any and all evidence of chemical weapons use within Syria.


Given the stakes involved, and what we have learned from our own recent experience, intelligence assessments alone are not sufficient – only credible and corroborated facts that provide us with some degree of certainty will guide our decision-making, and strengthen our leadership of the international community.

intelligence assessments alone are not sufficient    We can recall Colin Powell’s presentation to the United Nations and the New York Times’s reports on the aluminum tubes by Judith Miller, who was informed by those anonymous sources in the intelligence community.

That is why we are currently pressing for a comprehensive United Nations investigation that can credibly evaluate the evidence and establish what took place. We are also working with our friends and allies, and the Syrian opposition, to procure, share and evaluate additional information associated with reports of the use of chemical weapons so that we can establish the facts.

The United Nations has approved an investigation into the chemical weapons claims, but Syria has refused entry to the investigators entry.

More questions here.

Because President Obama has stated that use of chemical weapons by the Syrian government would cross a red line or be a “game-changer,” anyone who wants American intervention in the Syrian civil war has a motive to make the case that the government has used chemical weapons. Faking the evidence is all too easy.

What now? The letter is clear: a better case must be made than sarin found in blood samples that lack a chain of custody, with little or no indication of who was exposed and how.

More than a hundred thousand people have been killed in Syrian fighting. The civil war endangers the peace in surrounding countries, which are also taking in Syrian refugees, whose lives have also been seriously disrupted. It is a humanitarian catastrophe.

What can the United States do? Russia backs President Assad and is highly suspicious of interventions in other countries’ civil disorders, partly because it faces some of its own. And US interventions in Iraq and Afghanistan offer cautionary lessons. We do not fully know the character of the Syrian opposition, whose factions are currently united by their desire to remove Assad. As in Egypt and Libya, those factions will find conflict with each other after Assad is gone.

So would the US intervene for a single use of chemical weapons that injured or killed a dozen or so people? How about a hundred? Presumably Pentagon, State Department, and White House planners are working out these scenarios.

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