Numerous polls show that Americans want to reduce our military presence abroad, allowing our allies and other nations to assume greater responsibility both for their own defense and for enforcing security in their respective regions.

But why haven’t we done so?

In his new book, The Power Problem, Christopher A. Preble contends that the vast military strength of the United States has induced policymakers in Washington to broaden the perception of the “national interest,” and ultimately to commit ourselves to the impossible task of maintaining global order.

Preble holds that the core national interest — preserving American security — is easily defined and largely immutable. In his view, military power is purely instrumental: if it advances U.S. security, then it is fulfilling its essential role.

Preble spoke at Cato about what we views as the proper role of the United States in the world.