A report the U.N. is expected to release on Monday may provide the foundation necessary for the U.S. and Russia to agree on how to disarm the Bashar Assad regime.
U.N. chemical weapons inspectors are expected to unveil their findings Monday following a reported Aug. 21 sarin gas attack. The Obama administration has been adamant that the regime gassed its own people, killing more than 1,400. The Russians, however, as known allies of Assad claim to have contradictory evidence.
Neither side has yet revealed the content of their intelligence. However, the Syrian government has for the first time this week admitted it has a chemical weapons cache it says it is willing to give up.
The U.N. has already stated that its information will not indicate blame for the attack, but at least it will establish a middle ground from which to grow, experts say.
"That, itself, will have a lot of derivative value as the U.S. and Russia work through the Syrian disarmament plan," says Jon Wolfsthal, who previously worked as a non-proliferation special advisor to the White House National Security Council and to Vice President Joe Biden.
The rebels unlikely built rockets and acquired sarin gas to launch against their own people, he says, leaving the conclusion that it was either a deliberate attack by the Syrian regime or that the regime is no longer capable of securing its facilities during the civil war.
"It will add weight for the need for Syria to secure and declare its chemical weapons stocks," says Wolfsthal, now the deputy director at the Center for Nonproliferation Studies at Middlebury College's Monterey Institute of International Studies. .
"What the inspectors will be able to see isn't going to be proof," says Bruce Bennett, a senior analyst at the Rand Corporation who previously served as a counter proliferation official with the Department of Defense. "It's going to be something that's going to imply that is possibly the case."
"We're still going to see some heavy debates on what happened," he says.
Sarin is also a very tricky substance to investigate, Bennett adds. It evaporates like water and one-thousandth of a gram can be lethal.
Security expert Tom Snitch was a senior advisor for the U.S. Arms Control and Disarmament Agency, and says the weight of the U.N. findings rests on how much information they are willing to release.
"Will they release the delivery method? Or, will they simply as a matter of statements of fact, say 'Yes. It was used'?" said Snitch.
The presence of spent rocket casings could pin the attacks squarely on the regime, he says, unlike if toxic gases were delivered in a more rudimentary way.
Foreign Policy cited an anonymous source earlier this week who says the United Nations will likely release enough information to implicate the Assad regime.
"I know they have gotten very rich samples -- biomedical and environmental -- and they have interviewed victims, doctors and nurses," FP's source said. "You can conclude from the type of evidence the [identity of the] author."
So far neither the U.S. nor Russia has revealed tangible evidence of the use of chemical weapons in Syria, though officials such as Secretary of State John Kerry claim he has seen irrefutable intelligence.
Both nations have likely kept their information confidential due to the natural inclination for intelligence services to protect their "sources and methods."
"I've been surprised that the U.S. has not chosen to say more about the actual evidence," says Bennett. "I guess they thought their conclusions were compelling enough that people wouldn't doubt them."
Wolfsthal believes it's time for the U.S. to reveal the information, even if it compromises a source.
"If we are actually able to box in Assad to give up his chemical weapons stockpile, that's worth burning a lead or two," he says. "Given how the shadow of Iraq is hovering over everything that's going on here, the U.S. really has to go the extra mile to show our intelligence is not just circumstantial, but that it is compelling."