Original sentence: Politics, warfare and the environment are the main topics explored throughout the album, with songs such as "Rust in Peace... Polaris," which is about intercontinental ballistic missiles, and their effects on the world (Polaris refers to Polaris missile); "Take No Prisoners," which is about prisoners of war;  and "Holy Wars...The Punishment Due," which is a two-part song containing "Holy Wars," which is not referring to any historical place or event (although, according to some sources, was influenced by the reaction of the crowd to Mustaine's comment about unity of Ireland during a concert which took place there, despite the obvious reference to Israel on the lyrics)  and "The Punishment Due," which is about the Marvel Comics character The Punisher, of which Mustaine was a huge fan at the time
Edited sentence: Politics, warfare and the environment are the main topics explored throughout the album, with songs such as "Rust in Peace... Polaris," which is about intercontinental ballistic missiles, and their effects on the world (Polaris refers to Polaris missile); "Take No Prisoners," which is about prisoners of war;  and "Holy Wars...The Punishment Due," which is a two-part song containing "Holy Wars," which is not referring to any historical place or event (although, according to some sources, was influenced by the reaction of the crowd to Mustaine's comment about Northern Ireland during a concert which took place there, despite the obvious reference to Israel on the lyrics)  and "The Punishment Due," which is about the Marvel Comics character The Punisher, of which Mustaine was a huge fan at the time