tius, a war is just if three basic criteria were met: 1) the danger faced by the nation is immediate; 2) the force used is necessary to adequately defend the nation's interests; and 3) the use of force is proportionate to the threatened danger.(40) Grotius grounded his agreement with Cicero's notion of the need for a declaration of war in the natural law, and also argued that the purpose of just war theory is to provide "succour and protection for the sick and wounded in war, combatants and civilians alike."(41) A result of this view is the notion that just war theory exists externally of any recognised legal system, that it is a part of the "law of nations" which is followed by all civilised nations.(42) For Grotius, it is not necessary to prove just war theory by consulting with any of the established laws of the nations of Europe, or their customs.(43) Rather, those laws are known through the universal medium of the natural law, a law which transcends nations and their own particular legal codes, a law which is binding on all human societies in their interactions with each other.(44) After Grotius, just war theory underwent relatively few modifications until the nineteenth century. During the first century of it's existence, the United States' government came to acknowledge the legitimacy of just war theory. In 1842, the U.S. Secretary of State, Daniel Webster, acknowledged the legitimacy of the customary norms employed by Grotius to define the just war.(45) This recognition occurred as a result of attempts to resolve the so-called "Caroline Incident."(46) The Caroline Incident occurred when the British attempted to prevent supplies from reaching Canadian rebels.(47) In their attempts to restrict the flow of material to the rebels, the British burned the U.S. ship Caroline and killed several U.S. citizens.(48) When the United States protested, the British government responded that its actions were justified as a matter of self-defenc...
