Songfacts®:

• "Soldier On!" is a thundering song where Dave Mustaine draws parallels between images of war and walking away from a relationship.
  
  Of all the battles won and lost
  The lives and treasures that it costs
  I know I've got to soldier on
  
  According to Mustaine, the song is about "the shenanigans that were taking place in the band and in our presence, and sometimes behind our backs." He's likely referring to his firing of bassist David Ellefson from the band following allegations of sexual misconduct with an underage fan.
• Mustaine and Ellefson had been longtime bandmates and friends, and the Megadeth frontman needed to be brave to walk away from their relationship. "It's like that Irish poem about turning your collar up against the wind and having the sun shine on your face," he told Kerrang. "It's about being in that relationship, knowing that something is not right, and understanding that you need to leave."
• After Mustaine fired Ellefson, he brought in Testament's Steve DiGiorgio to play on this song and the other The Sick, The Dying... And The Dead! tracks. The album is also the first to feature former Soilwork drummer Dirk Verbeuren, who really makes his presence known on this song's chorus. "Having a new rhythm section doesn't affect how I approach things, but it certainly changes the way things are approached," Mustaine told Apple Music. "When you have different people involved, there's going to be different recording techniques and different psychology involved. In that situation, communication is one of the most important things."
• Megadeth performed "Soldier On!" live for the first time on September 20, 2022, during the band's concert in Syracuse, New York.