ISIS is not the legitimate government of Iraq. They are a terrorist organization that mass murders groups that do not believe what they believe. We are there as a part of an International Coalition.

http://www.forces.gc.ca/en/operations-abroad-current/op-impact.page

Killing fields? Talk about propaganda. And yes, if I were young enough and if I were in top condition I would volunteer. Being good enough for the JTF2 is another question.