After the end of Persian Gulf War in 1991, Colin Powell, then chairman of the Joint Chiefs of Staff, outlined his vision for efficient and decisive military action. His plan is now referred to as the Powell Doctrine, although there is not an actual formal document named as such. Powell, currently the U.S. secretary of state, has recently invoked the Doctrine in articulating the justifications for the Bush administration's preparations for war in Iraq. Essentially, the Doctrine expresses that military action should be used only as a last resort and only if there is a clear risk to national security by the intended target; the force, when used, should be overwhelming and disproportionate to the force used by the enemy; there must be strong support for the campaign by the general public; and there must be a clear exit strategy from the conflict in which the military is engaged.
Powell based this strategy for warfare in part on the views held by his former boss in the Reagan administration, Secretary of Defense Caspar Weinberger, and also on his own experience as a major in Vietnam. That protracted campaign, in Powell's view, was representative of a war in which public support was flimsy, the military objectives were not clear, overwhelming force was not used consistently, and an exit strategy was ill defined.