Why is president Obama attacking Syria?

I just started hearing about this a week ago and I've kind of tuned into it since. But I don't know why he's doing it. The only thing I got from it was that they had chemical weapons and he wants to remove them. I honestly don't understand the logic there. I mean so what if they have chemical weapons. I haven't heard anything on Syria trying to use the chemical weapons on us or anything threatening. I mean aren't there a bunch of other countries with chemical weapons also? If so, I don't see Obama going after those countries too. So why is he attacking Syria? If you ask me, this all seems uneeded and just stupid.