Right now four countries - Syria, Iraq, Lebanon, and Iran - and at least two militias - Syrian Kurds and Iraqi Kurds - are battling ISIS(IS).
Guess who isn't?
The US. The US has offered essentially no assistance.
And the EU and NATO are sitting on their hands too.
But, oddly enough, Russia has and is providing assistance to those battling ISIS(IS).
Note: The Iraqi Kurdish Peshmerga, Syrian Kurds, and the Iraqi Air Force are all together battling ISIS(IS) is northern Iraq right now, trying to save the Yazidis and the largest dam in Iraq.
Why do I include Iran? The Peshmerga consist of two groups and one of them has good relations with Iran and I have heard that Iran is helping and providing some supplies to that Peshmerga group which is battling ISIS(IS) in central eastern Iraq (at the southern edge of Iraqi Kurdistan.
There are two good diaries up now with more information: