I personally think the hysteria is with the media and establishment that have led Trump to carry out this action.
It goes against everything he has said.
Where is the evidence that this was Assad? I haven’t seen it.
Neither have I—at least not all of it. But it' is being presented on the news: flight paths, aerial photos, etc. A prima facie case seems to exist.
I presume the President, the intelligence community, Secretary of Defense Mattis, the Chiefs of Staff, and all other relevant advisors and Cabinet members have seen the "evidence that this was Assad", and believe it to be convincing.
Do you really think this administration would act irresponsibly in this instance? I honestly see no basis for such conjecture...