4
offensive “divide and conquer” variety—wherein adversaries are isolated from allies before
being picked off.
But wedge strategies in the defensive mode are at least as important in
power politics; yet these are absent from the realist literature on balancing, where we would
expect to find them conceptualized, described, and analyzed.
The problem of “unobserved balancing,” notes Jack Levy, happens when observable
balancing behavior does not occur because others anticipate it and are thus restrained. This
leads to “a systematic underestimation of the causal importance of balancing in international
politics.”
The same can be said for a more elementary problem of unobserved balancing,
the one that arises when scholars do not see balancing behavior that does occur—like wedge
strategies—because their concepts of balancing hide it. Hence, to understand why wedge
strategies are slighted in IR we need first to correct conceptual tendencies that tend to blind
us to their presence and importance.
Defining “Balancing” and “Wedge Strategy”
Power is relative—all students of IR know this. That means, ceteris paribus, a state can
increase its power over another by adding to its own capabilities, or by subtracting from
those of the other side. But most definitions of balancing have an “additive” bias; they imply
that states can only increase their relative power by adding to or “aggregating” their
capabilities.
To think clearly about wedge strategies we need to start with a definition of
132. At the apex of the relevant literature stands George Liska’s Nations in Alliance (Johns Hopkins University
Press, 1968) which gives sustained analysis of reasons for “dealignment” and “realignment,” including outside
pressures: pp. 42-60. Next is Glenn Snyder’s, Alliance Politics (Ithaca: Cornell University Press, 1997), which
devotes two pages to the subject of “divide and rule”: pp. 337-38. In their chapter on “different methods of the
balance of power” Hans J. Morgenthau and Kenneth Thompson give two paragraphs to the subject of “divide
and rule”: Politics Among Nations: The Struggle for Power and Peace, 6
th
edition (McGraw Hill, 1987), pp.
198-99.
9
For a recent and very clear treatment, see Patrick M. Morgan, International Security: Problems and Solutions
(CQ Press, 2006),p. 64. The offensive divide-and-conquer role is also touched upon in Walt, “Keeping the
World Off-Balance,” p. 140; Robert Powell, “War as a Commitment Problem,” International Organization,
Vol. 60, No. 1 (January 2006), p. 196; and Victoria Tin-Bor Hui, “Toward a Dynamic Theory of International
Politics: Insights from Comparing Ancient China and Early Modern Europe,” International Organization, Vol.
58, No. 1 (January 2004), p. 18. Also see Daniel Byman and Matthew Waxman, The Dynamics of Coercion
(Cambridge University Press, 2002), pp. 171-72. Related discussion appears in John Mearsheimer, Tragedy of
Great Power Politics (New York: Norton, 2001), pp. 153-54.
10
It is suggestive that Walt’s “Keeping the World Off-Balance,” which explores ways in which an American
hegemon can short-circuit counter-balancing, the conceptual equivalent of wedge strategy (same idea but
different terms) is discussed, but in Walt’s “Taming American Power,” which details a half-dozen ways in
which weaker states can “balance U.S. primacy” and form “counterpoise[s] to U.S. dominance” there is no
mention of wedge strategies or the conceptual equivalent.
11
“Balances and Balancing,” p. 138.
12
Robert Art’s definition of balancing behavior is a most explicit example: “behavior designed to create a better
range of outcomes for a state vis-à-vis another state or coalition of states by adding to the power assets at its
Convention