Combat Rock was originally planned as a double album with the working title Rat Patrol from Fort Bragg, but the idea was scrapped after internal wrangling within the group. Mick Jones had mixed the first version, but the other members were dissatisfied and mixing/producing duties were handed to Glyn Johns, at which point the album became a single LP. The original mixes were later bootlegged. Out-takes included a Tymon Dogg song, "Once You Know", the recording featured all the band with Tymon Dogg on vocals and violin.
In January 2000, the album, along with the rest of the Clash's catalogue, was remastered and re-released.
According to author Marcus Gray, the song "Red Angel Dragnet" was inspired by the January 1982 shooting death of Frank Melvin, a New York member of the Guardian Angels. The song contains extensive quotes from the 1976 movie Taxi Driver 's main character, Travis Bickle, delivered by Kosmo Vinyl. Bickle sports a mohawk in the later part of the film and that hairstyle was adopted by Joe Strummer during the album promotion.
The song, "Ghetto Defendant", features beat poet Allen Ginsberg, who performed the song on stage with the band during the New York shows on their tour in support of the album. At the end of the song he can be heard reciting the Heart Sutra, a popular Buddhist mantra.
In a contemporary review for The Village Voice, Robert Christgau lamented the same attempts at funk and dub the Clash had tried on Sandinista! (1980). Nonetheless, he dismissed the notion the band were selling out and believed they were "evolving" on Combat Rock, writing songs at a "higher level of verbal, musical, and political density", albeit in less "terse and clear" fashion than on their early work. Douglas Wolk said in a retrospective review for Blender that while the record was originally seen as the Clash's "sellout move" because of its danceable sound and two hit singles, the other songs featured "audaciously bizarre arrangements and some of Strummer's smartest lyrics."Q magazine was less enthusiastic, deeming it "their biggest seller, but the beginning of the end." In 2000, Alternative Press called it "the penultimate Clash album...employing lessons learned in the previous three years...their most commercially rewarded release...containing [their] most poignant song 'Straight To Hell'."CMJ New Music Report ranked Combat Rock at number five on its 2004 list of the Top 20 Most-Played Albums of 1982.Slant Magazine listed the album at No. 80 on its list of "Best Albums of the 1980s".Kurt Cobain listed it in his top fifty albums of all time.