The record was primarily promoted through the Into the Wild Tour, which earned the band a Guinness World Record for most live shows during a single album cycle, with 300 shows. It reached the top ten of several national album charts and has since sold over four million copies worldwide. This Is War received general acclaim from critics, who praised its instrumentation and experimental direction, and was nominated for the Echo Music Prize. It was accompanied by the documentary film Artifact (2012), which chronicled the dispute. Lyrically, it is a conceptual record shaped by the band's personal struggles and legal battle with their record label, and is sometimes considered a rock opera.
The album marked a departure from the band's previous material, implementing a more experimental direction that draws influence from progressive rock, new wave, industrial, and heavy metal music. The case was later settled in April 2009, and the band signed to EMI later that year. The album was recorded over a span of two years while the band was in the midst of a legal dispute with Virgin over an alleged breach-of-contract. It was the band's first studio album in four years, after the breakthrough of their previous work, A Beautiful Lie (2005).
This Is War is the third studio album by American rock band Thirty Seconds to Mars, released on Decemthrough Virgin Records and EMI.