There is no doubt WMD’s were used. The question is who used them.
Check it out:

Secretary of State John Kerry said Sunday that the United States now has proof that lethal sarin gas was used in Syria on civilians, in building the administration’s case of a military strike on the Middle East country.

Kerry told “Fox News Sunday” that blood and hair samples taken from first-responders in Damascus have tested positive for sarin.

“This case is going to build,” said Kerry, who also defended President Obama’s decision to seek congressional approval for a military strike.

“Our country is much stronger when we act together,” Kerry said. “I think this is a smart decision by the president, a courageous decision.”

The president was driven to make a decision, which he announced Saturday, after an Aug. 21 chemical attack outside Damascus that killed more than 1,400 people, including hundreds of children. The attack was just one of several allegedly carried out by Syrian President Bashar Assad after Obama said about 12 months ago that the regime using a chemical weapon would “cross a red line.”