In the past the USA "walked in" into some countries which didn't needed help.
But Syria does need help. They actually trying to change the situation in their country, may be even trying to build up a democracy, which is simply impossible for them with a dictator.
Asking what Syria has done for us is just a stupid question, what can they do when a dictator is leading the country?
I mean now there actually is a country which could need the help of the USA, and which wouldn't be invented because of the oil and stuff and now the USA should do nothing?