You can get "Why We Fight" at http://www.chomskytorrents.org/ -- it was apparently aired on BBC 4 Storyville not too long ago.
The premise is that the defense industry, but especially profit-hungry military contractors, drive America's imperialist adventures abroad. It uses Eisenhower's "military-industrial complex" speech as its basis and situates Ike as an ignored Jeremiah. However, it's worth watching for some of the interviews with folks like Donal Rumsfeld's speechwriter Ken Alderman, who in the film says he and Rumsfeld "had a saying around the office: 'Weakness is provocative, strength deters'" and when it goes intot he formation of the Office of Special Plans, the propaganda bureau responsible for whipping the US into war hysteria. It also provides a decent catalogue of US interventions abroad since the 40s. Not a perfect film, but absolutely worth a peak.
A low, maudlin point is when they play Nine Inch Nails' "Hurt" during a montage of combat scenes in Iraq. That part definitely deserves the "mute" button.
-B.