The former, especially considering Syria hasn't used them and doesn't have any.
America knows that, of course, having been the ones Syria delivered them to for destruction four years ago. They were afraid that destroying those chemicals on land would've been too dangerous if anything happened, so the US Navy took them out to sea.
Now suddenly it's okay to just lob a few missiles at buildings in the middle of a densely populated city, releasing god knows what into the air, and that won't cause any harm to the people living there? Is that the logic?
The hague organization for the prohibition of chemical weapons (OPCW) supervised the destruction of all syrian chemical weapons factories and stockpiles four years ago and certified the place free and clear.
Now in response to the allegations Syria has somehow regained chemical weapons, the OPCW went back to Syria. They were going to begin another investigation, but the air strikes were timed to happen 4AM the night before.
Now if the OPCW, the people who's job it is to discover chemical weapons stores & factories, haven't done that yet, how does the USA know where they are? Mystic Meg's premium rate hotline? We already know one of the buildings targeted in the strike was the OPCW's temporary base of operations in a snake venom antidote factory!
They must think we're stupid.