Songfacts®:

• In this song, Metallica rally the troops, joining their fans to form a "metal militia" ready to take on the world. It's one of the earliest Metallica songs, and while the lyrics are a bit uneven ("The metallization of your inner soul...") the message comes through. Musically, it's a burst of feral thrash metal that shows off the sound they refined to become the biggest metal band of the era.
• "Metal Militia" is the last track on Kill 'Em All, Metallica's debut album. It's credited to James Hetfield, Lars Ulrich and Dave Mustaine, but according to Mustaine, Ulrich had no part in the writing.
  
  "James and I wrote 'Metal Militia' and 'Phantom Lord,'" he told Songfacts in 2022. "Every note. And somehow, on the record it says Lars gets 10%."
  
  Mustaine was the original lead guitarist in Metallica but was fired before the album was released, with his parts re-recorded by his replacement, Kirk Hammett. The reason for his dismissal: drug and alcohol problems, a classic case of the pot accusing the kettle of being black. Mustaine formed Megadeth and took his place as one of the biggest names in metal, but his beef with Metallica lingered. Mustaine wasn't happy when they used songs he co-wrote (he also had a hand in "The Four Horsemen" and "Jump in the Fire"), and he was very unhappy when he saw the credits.
• The song appeared on Metallica's first tape of demo recordings, No Life 'Til Leather, recorded in the summer of 1982 with Mustaine and bass player Ron McGovney, who left soon after and was replaced by Cliff Burton. The tape circulated in the metal community and got a buzz for the band, but it's never been officially released because of the entanglements between Mustaine and his former bandmates.
• In the late '90s, a group of motocross riders formed the Metal Mulisha, a nod to this song. This crew was led by Brian Deegan, an X Games star known for pulling insane tricks that often left him mangled when they didn't land. Metal Mulisha became a brand in 1997, offering clothing and riding gear.