I know they claim its in response to the 1993 IRA bombing in Warrington, England that killed two children and injured 54 people, but I think the lyric are clearly about this phenomenon.

In your head, in your head, they are fighting - Most of the war you will fight when satan comes for you happens in your head.

Zombie, zombie - What you become once satan has captured you, a living dead or zombie

In the sense that all wars and disasters on earth are caused by satan, then it is true it is also about the  IRA situation, and all these others