If war is in iraq; Islam which is the home of Allah, how come there is war there?

I was reading about a marine who has sadly passed from an overdose of drugs, his name was William wold. A marine who was just about to be sergeant in the corps, but didn’t want to re-enlist at the time. While he was in fallujah, it was said he shot 6 men dead inside of a mosque, a place where I swear Allahs protection was greatest.. somehow breached? How? Why? How come it seems everyone targets Islam?