WaPo: "Unverifiable claims: You’d be an idiot if you didn’t approach this thing with a bit of caution.”

[WaPo] "UNITED NATIONS — Despite months of laboratory testing and scrutiny by top U.S. scientists, the Obama administration’s case for arming Syria’s rebels rests on unverifiable claims that the Syrian government used chemical weapons against its own people, according to diplomats and experts....
The technical data presented by the three Western powers is of limited value to U.N. inspectors trying to determine whether
Syria’s combatants used chemical weapons during the country’s 25-month-old conflict. Under the United Nations’ terms of reference, only evidence personally collected by its inspectors can be used to fashion a final judgment.
But no inspectors have been allowed inside Syria, so Western governments have relied on physical evidence smuggled out of the country by rebels or intelligence operatives. Precisely who acquired the evidence and what methods were used to guard against tampering may be unknowable, according to experts experienced at investigating chemical weapons claims.
“You can try your best to control the analysis, but analysis at a distance is always uncertain,” said David Kay, a former U.N. weapons inspector who led the U.S. search for weapons of mass destruction in Iraq after the 2003 invasion. “You’d be an idiot if you didn’t approach this thing with a bit of caution.”..., ..., ....
U.S. officials staunchly defend what they describe as an extensive, rigorous and multilayered analysis that led to the White House’s June 13 pronouncement on the use of chemical weapons in Syria. The conclusion that Assad’s forces used sarin was based on scientific assessments ...
Having been famously burned by the 2003 intelligence failure over Iraq’s alleged weapons of mass destruction, U.S. analysts now approach all such claims with exceptional care, said a third administration official familiar with intelligence analysis...."