Sqad -- I don't think policies should be set in stone, so in that sense that Trump responded to what was actually happening is perfectly sensible. It does raise the question as to why, when the same thing was happening in 2012/2013 he didn't seem to care about the children being gassed, although the easy and perhaps accurate answer to that is that now he isn't free to bluster about what should and shouldn't be done now that he's the one who has responsibility.
The problem comes because of the speed of the change, the fact that it's so far the US acting alone on this, and questions I'd have about the motivation. If it's a direct and unqualified response to the chemical attack borne of human decency then it's well-motivated but still very rushed. It's the speed of the change, and lack of coordination with other nations, that makes me a little uneasy about it. I think it's right to act in a way other than meaningless protest in response to the War in Syria, but I'd still have hoped for a coherent and measured national response. This on its own achieves little, and doesn't seem to have been thought through completely.
Still, if it at least gives Assad pause for thought before launching another such attack, it will have been worth it. Anything more than last night's strikes needs far more time and care behind it.