During the U.S. invasion of Iraq, Syria’s Assad regime was helping insurgents to cross the border and kill Americans.
So too is the atavistic attachment to a regime that not only has killed thousands of its own citizens, but contributed to the deaths of dozens if not hundreds of U.S. troops and contractors in Iraq.
https://newrepublic.com/article/86465/syria-assad-bush-obama-pentagon
Israel has struck Syria a dozen times or so with bombs, the US made this one pinprick attack. I have no sympathy for Assad per above or for his father who helped in the bombing of 250 Marines; http://articles.latimes.com/1988-10-23/news/mn-348_1_marine-barracks
What I think is going to happen is Assad is going to be pressured to stand down, perhaps in the long run, Putin is in decline too. Trump did the right thing.
I think the Trump admin. has a good lead on Assad, his Dr. Gas and everything going on: https://www.thesun.co.uk/news/3296175/family-of-assads-weapons-chief-dr-gas-living-life-of-luxury-in-london-as-children-die-back-home-in-syria/
Not the mickey mouse conspiracy sites.
http://www.nationalreview.com/article/446504/syria-gas-attack-us-response-military-russia-isis-obama
As the map shows, ISIS isn’t even in the area, in control of at least; Putin and Assad aren’t fighting ISIS.