Why don't the so called "Gangsta's" like Crips and Bloods go fight in Iraq a proper war zone?

They seem to love gunslinging so much in the streets, but why don't they go fight for their countries in real war torn countries?? You always hear about these wannabe Gangsta's who try to be like "scarface" type chracters, but i don't see many of them signing up for the real deal!??