With the publication of "Air Theory for the Twenty-first Century," Colonel John Warden ushered in a new era of wartime targeting. No longer are warfighters limited, as in years past, to an ad hoc, haphazard system of selecting wartime targets. Rather, Warden presents the warfighter with a unique tool "the five-ring system theory" that dramatically improves the warfighter's ability to systematically identify wartime targets.