When you add two even numbers and your answer is an odd number, you have to suspect you are wrong. When you conclude the Syrian government launched the sarin gas attack, you get an odd number, you have to wonder why the answer is also odd. Carla Del Ponte., speaking of the first gas attack, told the UN that her investigation revealed concrete suspicions that the rebels had actually launched the attack.
"Our investigators have been in neighboring countries interviewing victims, doctors and field hospitals and, according to their report of last week which I have seen, there are strong, concrete suspicions but not yet incontrovertible proof of the use of sarin gas, from the way the victims were treated."
"This was use on the part of the opposition, the rebels, not by the government authorities."
Del Ponte is a former prosecutor and former Swiss Attorney general, as well as a long time investigator for the UN. Ms Del Ponte also served as the prosecutor in the International Criminal Tribunal for the former Yugoslavia for the UN. In the inquiry into the sarin attack in Syria, she was acting for an investigation out of Geneva on war crimes.
Del Ponte claimed that she was surprised by the evidence that it was the rebels and not the Syrian government, who may be responsible for those attacks.
"I was a little bit stupefied by the first indications we got... they were about the use of nerve gas by the opposition."
The April attack came at an advantageous time for the rebels, as they were trying to get the UK and the US to aid them by sending them arms. The recent attack came at an equally advantageous time, just as Assad's military was pushing rebel forces out of their strongholds and in some cases, having them surrounded. The rebels, mostly Al Qaeda claimed they didn't even have the capability to launch such an attack.
In June, a raid on three Al Qaeda workshops, uncovered manufacturing of both mustard and sarin gas in Iraq. Iraq borders Syria. In the raid, they also found radio controlled airplanes with a range of at least a mile. Another suspicious item is that the gas attacks happened in residential areas and not in the rebel camps.
This has led to speculation that Al Qaeda could have been behind the attacks in order to draw in the UK and the United States into the conflict, just as they were being driven back.
The Associated press interviewed several intelligence sources, who told them that the assumption that the Syrian government was behind the attacks was anything but a slam dunk. This is from the AP story:
"We have concluded that the Syrian government in fact carried these out," Obama said in an interview with "NewsHour" on PBS. "And if that's so, then there need to be international consequences."
However, multiple U.S. officials used the phrase "not a slam dunk" to describe the intelligence picture — a reference to then-CIA Director George Tenet's insistence in 2002 that U.S. intelligence showing Iraq had weapons of mass destruction was a "slam dunk" — intelligence that turned out to be wrong.
A report by the Office of the Director for National Intelligence outlining that evidence against Syria includes a few key caveats — including acknowledging that the U.S. intelligence community no longer has the certainty it did six months ago of where the regime's chemical weapons are stored, nor does it have proof Assad ordered chemical weapons use, according to two intelligence officials and two more U.S. officials.
If intelligence doesn't know where the weapons are and who has control, it's virtually impossible to say with any certainty who launched the attack, and when you consider the attack hurts the Assad government and aids the Al Qaeda rebels, it foments doubt.