Chapter 4 Summary - PLS 220
I. The Notion of a System
is an assemblage of units, objects, or parts united by some form of regular interaction.
In the 1950s, the behavioral revolution in the social sciences and growing acceptance of political realism in
international relations led scholars to conceptualize international politics as a system, using the language of systems theory.
II. The International System According to Realists
All realists characterize the international system as anarchic. No authority exists above the state, which is sovereign.
Each state must therefore look out for its own interests above all.
Polarity: system polarity refers to the number of blocs of states that exert power in the international system. There are
three types of polarity:
if there are a number of influential actors in the international system, a balance-of-power or
multipolar system is formed.
In a balance-of-power system, the essential norms of the system are clear to each of the state actors.
In classical balance of power, the actors are exclusively states and there should be at least five of them.
If an actor does not follow these norms, the balance-of-power system may become unstable. When
alliances are formed, they are formed for a specific purpose, have a short duration, and shift according to advantage rather than
in the bipolar system of the Cold War, each of the blocs (the North Atlantic Treaty Organization,
or NATO, and the Warsaw Pact) sought to negotiate rather than fight, to fight minor wars rather than major
ones, and to fight major wars rather than fail to eliminate the rival bloc.
Alliances tend to be long term, based on relatively permanent, not shifting, interests.
In a tight bipolar system, international organizations either do not develop or are ineffective. In a
looser system, international organizations may develop primarily to mediate between the two blocs.
one state that commands influence in the international system.
Immediately after the Gulf War in 1991, many states grew concerned that the international system
had become unipolar, with no effective counterweight to the power of the United States.
System Management and Stability: Realists do not agree among themselves on how polarity matters.
Bipolar systems are very difficult to regulate formally, since neither uncommitted states nor international
organizations are able to direct the behavior of either of the two blocs. Informal regulation may be easier.
Kenneth Waltz argues that the bipolar system is the most stable structure in the long run because there is a
clear difference in the amount of power held by the two poles as compared to that held by the rest of the state actors.