They think they will "punish" Syria with some cruise missile attacks and there will be no retaliation on Syria's behalf. Syria is not Iraq,or Libya. They have fought the best army in the world the IDF. Yes Syria has lost to the IDF, but it has learned from those encounters, and they will retaliate one way or another. Also a government in a democratic society that goes against the opinion of the people, is no better than the autocratic regimes in wants to topple.
Jordan foreign minister says to speak with Kerry on Israel-Palestinian conflict (Reuters)