Of course you will not be exposed to such evidence since you live in a Western country, and are shown the Western perspective of things. The US would never perform an action to achieve a particular goal and have internal sources cause controversy, meaning Western sources proving the evidence you're seeking simply don't exist.
The only way for someone who's not knowledgeable on the topic to really understand what's going on, is to either personally travel there (or to access local media, but there might be a language barrier there).
ISIS protecting Syria? From what? If ISIS didn't exist, Syria would be safe.