Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
Waltz. 1979. Theory of international politics. Reading, MA: Addison-Wesley.
CHAPTER 1: Laws and Theories
Although laws might just describe a correlation (with a given probability), theories explain them.
CHAPTER 4 (from summary)
Theories of international politics deal with events at both the sub- and supra-national levels. "Reductionist" theories explain "the behavior of parts"--they seek to explain international outcomes solely through the behavior of units, leaving aside the effect their environment may have. However, "it is not possible to understand world politics simply by looking inside of states." (p. 65) This is because every new observed phenomenon would require the addition of new unit-level variables, which leads to the highly subjective addition and wild proliferation of variables.
Moreover, though the actors and nature of actors in international politics change significantly, patterns of international politics recur. "If the same effects follow from different causes, then constraints must be operating on the independent variables in ways that affect outcomes." (p. 68)
A system-level explanation of world politics solves both of these problems. By focusing on the structure, or "set of constraining conditions," (p. 74) of the international system one can parsimoniously explain why dissimilar units may behave in similar ways. Structures, however, are not direct causes--they act "through socialization of the actors and through competition among them." (p. 74)
CHAPTER 5: Political Structures (my notes)
A structure is defined first by the principle by which it is ordered or organized, then by the differentiation and specification of its units, and finally by the distribution of capabilities across units.
For Waltz, anarchy, or the absence of central authority, is the ordering principle of the international system. By analogy to microeconomic theory, Waltz argues that international systems emerge from the "coaction of self-regarding units." (p. 91) In a microtheory, whether economic or political, the motivation of actors is assumed rather than realistically described. Waltz assumes that "states seek to ensure their survival." The real aims of states may be endlessly variable, but in a world without security survival is the essential prerequisite and thus a useful foundation for the theory. "Internationally, the environment of states' action, or the structure of their system, is set by the fact that some states prefer survival over other ends obtainable in the short run and act with relative efficiency to achieve that end." (p. 93).
The second aspect of structure, the differentiation of units, is rendered unnecessary by the condition of anarchy. "Anarchy entails relations of coordination among a system's units, and that implies their sameness. ... [S]o long as anarchy endures, states remain like units." (p. 93) Which is to say they are "autonomous political units" (p. 95) who face similar tasks. While Waltz recognizes the existence of non-state actors, he dismisses their importance because states are still the most powerful actors on the world state--they have the most influence and they set the rules. Thus, the international system is defined in terms of states.
"Students of international politics make distinctions between international-political systems only according to the number of their great powers. The structure of a system changes with changes in the distribution of capabilities across a system's units." (p. 97) Although this may seem to violate the notion that structure must be defined independently of the attributes of units, Waltz argues that "although capabilities are attributes of units, the distribution of capabilities across units is not." (p. 98) The key result from this approach is a "positional picture" that describes a system "in terms of the placement of units rather than in terms of their qualities." (p. 99)
CHAPTER 6 (from handout)
Anarchy does not imply that violence is common in the international system but rather that the threat of violence is ever present. Anarchy means that the international system is one of self-help. Waltz identifies two ways in which the structure of the international system limits cooperation. First, "the condition of insecurity--at the least, the uncertainty of each about the other's future intentions and actions--works against their cooperation. ... A state worries about a division of possible gains that may favor other more than itself." (pp. 105-6) Second, "a state also worries lest it become dependent on others" through trade and/or cooperation, and therefore also chooses to limit its cooperation with other states. (p. 106) "States do not willingly place themselves in situations of increased independence. In a selfhelp system, considerations of security subordinate economic gain to political interest." (p. 107). The structure of the system forces states into this kind of behavior; the only way out is structural change. Nevertheless, Waltz sees virtues in anarchy--principally that the high costs of organization in a hierarchic order are avoided and that states can preserve their autonomy.
Balance of Power Theory (pp. 116-128 in chapter 6): [still from handout]:
In seeking to test his theory, Waltz arguing that confirming cases (as opposed to just falsifiable cases) are acceptable, particularly if hard cases (those where you would not expect the theory to hold) are chosen. He also suggests that one should infer empirically verifiable predictions. However, he concedes that balance-of-power theory's predictions are indeterminate; it posits only a loose condition of balance, and thus it is unclear when that condition does not hold. Also, internal conditions may preclude states from balancing consistently see balancing behavior, even in cases where one would not ordinarily expect--he points to the French-Russian alliance of 1894 or the U.S. and Soviet decisions to rearm after WWII.
Finally, Waltz contrasts balancing with bandwagoning, in which weaker states choose to ally with the stronger state. Waltz argues that "because power is a means not an end, states prefer to join the weaker of two coalitions." (p. 126) Again, the structure of the international system and the necessity of survival dictate this behavior.
CHAPTER 8: ALLIANCES
In this section, Waltz investigates how changes in the structure of the international system affect alliances. He focuses, in particular, on the difference between multi-polar and bi-polar alliance systems.
He defines multi-polar systems as those containing more than two major powers, finding most distinctions between different multi-polar systems as generally faulty.
The primary difference between multi-polar and bi-polar balancing is that multi-polar balancing occurs externally (among states), while bi-polar balancing occurs internally. Because external balancing is more uncertain, bi-polar balancing tends to produce less conflict.
Waltz discusses several additional features of multi-polar balancing:
For bi-polar alliances:
POINTS TO CONSIDER [from handout]
For its parsimony and theoretical rigor, neorealism has been the baseline for most of IR theory over the last 20 years. It has prompted a rich literature critiquing it on a number of fronts: for instance, neoliberals say that it does not take seriously enough the possibility that states may choose absolute over relative gains, particularly in situations where institutions can alter payoffs; constructivists argue that its fails to recognize the manner in which agents and structures are mutually constitutive; and people from all over the map say that it is too generalized and yields little in the way of testable implications. Nevertheless, the theory has been hugely influential.
Research on similar subjects