http://www.newsweek.com/now-mattis-admits-there-was-no-evidence-assad-using-poison-gas-his-people-801542
Lost in the hyper-politicized hullabaloo surrounding the Nunes Memorandum and the Steele Dossier was the striking statement by Secretary of Defense James Mattis that the U.S. has “no evidence” that the Syrian government used the banned nerve agent Sarin against its own people.

This assertion flies in the face of the White House (NSC) Memorandum which was rapidly produced and declassified to justify an American Tomahawk missile strike against the Shayrat airbase in Syria.