system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Are ISIS the Syrian rebels the US government wanted to send arms to when the Syrian civil war broke out?

I seem to remember McCain and other senators saying they wanted us to send arms to help the Syrian rebels against Assad. As far as I'm aware ISIS is fighting Assad, so were we trying to send arms to them?
gpt
No.  There were several rebel groups fighting against Assad.  The one(s) the US was thinking of sending arms to were largely secular.

ISIS, however, has been more effective at building a solid fighting force in Syria and beyond.  The secular rebel groups are now a small minority of the rebels in Syria, and will probably have little to no say in a new government even if Assad falls.