Instability and Expansionism: Why the Former No Longer Produces the Latter in US Foreign Policy

Why is expansionism absent from the Obama foreign policy agenda? The question seems bizarre precisely because expansionism is so completely absent from US policy discussions. In the modern world, the lack of great-power expansionism in the international system may be overdetermined, but the single strongest deterrent against twenty-first-century expansionism is likely the US commitment to oppose it. This commitment, repeatedly confirmed both through military actions like the Gulf War and consistent diplomatic rhetoric, is rooted in the commitment of the US to reject expansionism in its own foreign policy. It is therefore not a stretch to say that much of the stability of the current international system is the result of the US decision to forgo expansionism in its own foreign policy, a decision that represented a 180° turn from the aggressive expansionism of early US foreign policy (despite Jefferson‘s words quoted above). Obviously, this decision cannot be explained by the US‘ own deterrent power, but neither can it be fully explained by any of the other major arguments concerning the current stability in the modern literature. This paper offers an answer to the question of why expansionism faded from US foreign policy after its heyday in the early 1800s.