'Why We Fight' is a 2005 documentary film by Eugene Jarecki about the military–industrial complex. The title refers to the World War II-era eponymous propaganda films commissioned by the U.S. Government to justify their decision to enter the war against the Axis Powers.

Why We Fight was first screened at the Sundance Film Festival on January 17, 2005, exactly forty-four years after President Dwight D. Eisenhower's farewell address. Although it won the Grand Jury Prize for Documentary, the film received a limited public cinema release on January 22, 2006. It also won one of the 2006 Grimme Awards in the competition "Information & Culture"; the prize is one of Germany's most prestigious for television productions and a Peabody Award in 2006.