“Holy Wars… The Punishment Due” is the opening track off Megadeth’s fourth studio album Rust in Peace. The song consists of two different parts.

The track’s first half, “Holy Wars,” is written about the religious conflict in Northern Ireland, which started in 1960, but has its roots as far back as the 17th Century.

The story of Dave Mustaine’s inspiration for the song is outlined in the liner notes of the 2004 re-release of Rust in Peace, originally taken from an interview with the UK magazine Guitarist.

Whilst on tour in Northern Ireland, he was dissuaded from “taking action” against bootleggers selling Megadeth t-shirts as they claimed it was to help “fund the cause.”

Dave liked the sound of “the cause” so dedicated a cover of The Sex Pistols' “Anarchy in the U.K.” (which appears on So Far, So Good… So What!) to it shouting “Give Ireland back to the Irish! This one’s for ‘the cause’—Anarchy in Ireland!” This resulted in a near riot and Megadeth had to leave the city of Belfast in a bulletproof bus, by police escort.

“The Punishment Due” was written in reference to the Marvel comic book The Punisher. Megadeth had also referenced The Punisher in an earlier song, “Killing Is My Business… and Business Is Good!”