Wedge Strategy

In international relations theory, a wedge strategy is the deliberate effort by a state to prevent, weaken, or break apart a hostile alignment by peeling off one or more of its members. The concept was systematized by Timothy W. Crawford, whose work — including Pivotal Deterrence (2003) and later writing on "selective accommodation" — argues that great powers routinely use inducements, threats, and side payments to keep rivals from combining against them.

Wedge strategies generally fall into two families:

• Rewarding wedges (selective accommodation): offering concessions, security guarantees, trade access, or recognition to lure a target away from its partners. Classic examples include Nazi Germany's 1939 Molotov–Ribbentrop Pact, which detached the Soviet Union from any anti-German front with Britain and France, and the Nixon–Kissinger opening to China in 1971–72, which widened the Sino-Soviet split.
• Coercive wedges: using threats, sanctions, or military pressure to make continued alignment too costly for the weaker partner. Bismarck's diplomacy after 1871, designed to keep France isolated, mixed both forms.

Scholars distinguish wedge strategies from ordinary balancing because the goal is coalition prevention rather than direct power aggregation. Success typically requires that the target's commitment to its allies be conditional, that the divider can credibly deliver its promises, and that the remaining coalition members cannot easily compensate the defector.

Wedge logic is frequently invoked in contemporary analysis of:

• Russian efforts to fracture NATO and EU consensus on Ukraine since 2014.
• Chinese diplomacy toward U.S. treaty allies such as the Philippines, South Korea, and members of ASEAN.
• U.S. attempts to widen distance between Moscow and Beijing, sometimes called a "reverse Kissinger."

Critics note that wedge strategies often fail or backfire: targets may pocket concessions without defecting, and visible divide-and-rule attempts can harden the coalition they were meant to break, as arguably occurred with NATO after 2022.