Throughout recorded history, rulers of states, kingdoms, or other political entities have entered into treaties with each other for the purposes of ending or averting violent conflict. However, the formation of the United Nations in 1945 created a means for the world community to enforce international law upon members that violate its charter. The trend towards multilateral commitments has accelerated since then, and it is now meaningful to study international law as a means towards resolving conflicts among states.

Traditionally, states were the sole subjects of international law,...