The world finally agrees that Bashar al-Assad used poison gas against Syrian civilians. Beyond that basic fact, riddles remain. No one is quite sure about exactly what kinds of chemicals his regime used, where precisely the Syrian military has struck, and when. Now, there's another seemingly ill-fitting piece to the confusing jigsaw puzzle. Mysterious rockets found at the scene of some of the alleged gas attacks may be conventional weapons that produce injuries that can resemble those resulting from a chemical attack.
A few weeks ago, Killer Apps displayed this video, titled "Chemical Massacre," showing what appear to be Syrian Republican Guard troops in Damascus firing a rocket in late August that looks incredibly similar to the odd-looking munitions found at the scene of alleged chemical weapons attacks in Syria over the last year, including those around Damascus on Aug. 21 that killed as many as 1,400 people.
Numerous observers of the weapons used in the Syrian civil war have speculated that the mystery rockets' warheads could easily be filled with nerve agents. Human Rights Watch even went so far as to say there is a chemical weapons variant of the unidentified 330-mm rockets in its report on the Aug. 21 attacks.
The rockets shown in that particular video, however, were likely conventional explosive devices; they were being used in broad daylight while the chemical attacks around Damascus have usually happened at night.
In either case, these rockets strongly resemble an experimental American weapon from the 1970s called the Surface Launch Unit-Fuel Air Explosive or SLUFAE. Fuel-air explosives (FAE) like SLUFAE, often called thermobaric weapons, are among the nastiest conventional munitions out there. These weapons use pressurized gas to create a massive explosion that relies on waves of air for its destructive power rather than using flames and shrapnel to destroy targets.
It might -- might -- be possible to mistake a strike with thermobaric weapons for a chemical attack, especially since thermobaric weapons aren't used very often.
"That's a thought that I've had, and another person that I've talked to who is an expert on chemical and biological warfare has also had that thought," Cheryl Rofer, a chemist who supervised a team destroying chemical warfare agents at the Los Alamos National Laboratory, said in response to a question about the possibility that people are confusing thermobaric strikes for some of the alleged chemical ones in Syria.
Rofer said that while the Aug. 21 attacks likely involved chemical weapons, some of the earlier strikes thought be by chemical munitions may have been conducted with thermobaric weapons instead.
"At the moment I'm inclined to go along with the intelligence reports . . . that say its chemical weapons but I have to say I wouldn't be surprised if we had somebody come out and say, ‘attack x was thermobaric'," said Rofer. "Frankly, I've had a lot of doubts about attributing a lot of these [incidents] to chemical attacks up until the intelligence reports came out. I really wish they would come out and give some of the evidence they've got because I think they could do that without damaging classified information."
Thermobaric weapons work by expelling a cloud of explosive gas -- sometimes mixed with explosive dust like finely ground aluminum -- from their warheads when they are just above their target, this cloud explodes a split second later, creating a tremendous shockwave of air. The largest thermobaric weapons are sometimes compared to small nuclear bombs.
The blast wave obliterates people close the detonation while crushing and destroying the internal organs of victims who are a little further afield. The weapons are especially useful for attacking buildings, bunkers or armored vehicles with open doors or hatches. The explosions often leave reinforced buildings or armored vehicles intact while killing people inside them. The lack of shrapnel or serious flames means the victims are often found dead with no external signs of injury.
"The effect of an FAE explosion within confined spaces is immense," reads this U.S. intelligence report on how thermobaric weapons produce casualties similar to chemical weapons. "Those near the ignition point are obliterated. Those at the fringe are likely to suffer many internal, and thus invisible injuries, including burst eardrums and crushed inner ear organs, severe concussions, ruptured lungs and internal organs, and possibly blindness."
A former U.N. weapons inspector told Killer Apps in an email that it could be easy to confuse a victim of a thermobaric blast with one suffering from a chemical attack. "I have seen videos of test animals that were killed in this fashion [by thermobaric weapons], they did not look as though they had been involved in a blast - no bleeding, etc," he wrote.
Making matters even more bewildering for observers is the fact that thermobaric weapons don't always explode when fired. When this happens, the highly toxic explosive fuel for the weapons is simply expelled into the atmosphere causing an accidental chemical weapons attack, according to the U.S. intelligence report.
"Injuries and deaths produced by blast effects of fuel-air explosives often are confused with those caused by nerve agents because of the virtual absence of visible physical damage," reads the intelligence report. "Injuries occurring when a fuel and dust-air explosive fails to detonate are true chemical injuries and are not a result of CW agents. Direct contact with these compounds causes irritation, skin corrosion, burns, and allergic reactions, all of which can be confused with chemical weapon injuries."
In fact, ethylene oxide, a colorless gas with a sweet odor, is one of the most common fuels used in thermobaric weapons. People exposed to ethylene oxide suffer a list of symptoms that sound an awful lot like what we've seen in reports of Syrian chemical attacks throughout the past few months -- vomiting, skin burns, eye irritation, nerve damage, seizures, weakness, difficulty breathing, fluid in the lungs, and more.
"Since the most common FAE fuels, ethylene oxide and propylene oxide, are highly toxic, undetonated FAE should prove as lethal to personnel caught within the cloud as most chemical agents" reads a U.S. Defense Intelligence Agency report on fuel-air explosives obtained by Human Rights Watch.
Ethylene oxide and propylene oxide "would not be very good for breathing," quipped Rofer when asked about the effect those particular chemicals would have on humans exposed to them. "We chemists like to understate things like that.
Rofer added that U.S. and European intelligence agencies should release the hard intelligence they have that proves a chemical attack in order to remove "this lingering doubt." (A United Nations report documenting such evidence is due out Monday.)
One way of determining which type of weapons were used would be to look at possible imagery of the rockets landing that might have been collected by American spyplanes or satellites. Chemical weapons don't produce massive explosions whereas thermobaric blasts would be very visible, according to Rofer.
All of this adds to the confusion of how often and how much chemical weaponry Assad has actually used against his own people. Regime forces are accused of using everything from tear gas to nerve agents and even possible combinations of the two since at least January. But there's a possibility that a third type of weapon has been used in some of these attacks -- a thermobaric one.
It's even possible that all three types of arms were used in the horrific Aug. 21 attacks. After all, one eyewitness said that, aftwards, the victims had radically different kinds of wounds.
"The dead bodies -- this is the strange thing -- the dead bodies, there were hundreds. And there were two kinds," opposition activist Razan Zaitouneh said after the strikes. The first continued to have foam come out of their mouths. "Another kind -- blood came out from their mouths and noses."
Perhaps we now have a clue about why that happened.
John Reed reports on the frontiers of cyber war and the latest in military technology for Killer Apps.