The balance of power is a decentralized system for managing of power relationships. Two ideas on the balance of power as a system merit attention. First, the balance of power is a “fallback system” of international relations; in a multistate system, unless an alternate system is established for the management of power, it is natural for states to take care of their own security. Second, the classical balance system of the earlier centuries has been modified by two major developments in this century; the establishment of general international organizations, and the creation of institutionalized alliances such as NATO. The correct option is D.