Balance of Power exists when there is parity or stability between competing forces. As a term in international law for a ‘just equilibrium’ between the members of the family of nations, it expresses the doctrine intended to prevent any one nation from becoming sufficiently strong so as to enable it to enforce its will upon the rest.
“BOP” is a central concept in neorealist theory. Within a balance of power system, a state may choose to engage in either balancing or bandwagoning behavior.