If everyone could understand clearly the advantages which he would gain from conformity to the principles of justice and equity and would exercise the perseverance and self-discipline which is necessary to give up satisfactions of the moment for his long-range interests, there would be no need for government or what may be called a political society. It is because this type of understanding and self-control is not shared by all the members of society that we have laws and regulations along with the power of the state to enforce them. The sole reason why these laws must be obeyed is the fact that they constitute a useful method for preserving peace and order among the citizens of the state.
Among the nations of the world, there is a similar need for principles of conduct by which their dealings with one another may be regulated. Within certain limits, we may say that the same principles of justice and equity which prevail among individuals are also necessary for the well-being of the nations. It is generally understood that even among nations that are at war with one another, there are some rules that should always be obeyed. The safety of ambassadors must be maintained, the use of poisoned weapons must be forbidden, humane treatment must be accorded to prisoners of war, and certain precautions must be observed to prevent the destruction of civilian centers of population. All of these rules are recognized as useful means for protecting the interests of states in general.
There are, however, some important differences between kingdoms and individuals in their relations with one another. This accounts for the fact that many of the rules and regulations which have to do with the conduct of individuals within a given state are suspended in the area of international relations. In fact, the obligations of states to respect their commitments to one another are not regarded as binding to the same extent as they are among persons belonging to the same political unit. States may violate their treaties or alliances with one another whenever it appears essential to their own interests to do so.
