The balance of power is a concept in international relations that refers to the posture and policy of a nation or group of nations protecting itself against another nation or group of nations by matching its power against the power of the other side. States can pursue a policy of balance of power in two ways: by increasing their own power, as when engaging in an armaments race or in the competitive acquisition of territory; or by adding to their own power that of other states, as when embarking upon a policy of alliances.
The term balance of power came into use to denote the power relationships in the European state system from the end of the Napoleonic Wars to World War I. Within the European balance of power, Great Britain played the role of the “balancer,” or “holder of the balance.” It was not permanently identified with the policies of any European nation, and it would throw its weight at one time on one side, at another time on another side, guided largely by one consideration—the maintenance of the balance itself.
The balance of power theory is a core tenet of both classical and neorealist theory and seeks to explain alliance formation. Due to the neorealist idea of anarchism as a result of the international system, states must ensure their survival through maintaining or increasing their power in a self-help world. With no authority above the state to come to its rescue in the event of an attack by a hegemon, states attempt to prevent a potential hegemon from arising by balancing against it. States happy with their place in the system are known as "status quo" states, while those seeking to alter the balance of power in their favor are generally referred to as "revisionist states" and aspire for hegemony, thus repairing the balance.
Some realists maintain that a balance-of-power system is more stable than one with a dominant state, as aggression is unprofitable when there is equilibrium of power between rival coalitions. When threatened, states may seek safety either by balancing, allying with others against the prevailing threat; or bandwagoning, aligning themselves with the threatening power. Other alliance tactics include buck-passing and chain-ganging.
In summary, the balance of power is a concept in international relations that refers to the posture and policy of a nation or group of nations protecting itself against another nation or group of nations by matching its power against the power of the other side. States can pursue a policy of balance of power in two ways: by increasing their own power or by adding to their own power that of other states. The balance of power theory is a core tenet of both classical and neorealist theory and seeks to explain alliance formation.
