As CIC., he can order the military to strike Syria. But he cannot declare war
He can start a war and not call it a war. In other words, he can defy the Constitution by using word games. Just because he did it before in Libya — and conservative monarchists like Coulter and Bolton are fine with it — doesn’t make unconstitutional actions constitutional.
“As CIC...”
He’s CIC after Congress declares war. Not before or until. As CIC, he gets to prosecute a war. The title does not confer on him the power or authority to start one. Neither does the Constitution.