Letter to the Editor:

Stephen Rosenfeld’s Jan. 8 op-ed column, “Predator’s Preference,” calling a libertarian foreign policy of military restraint overseas “profoundly neo-isolationist,” takes sharp issue with a paper I wrote.

In fact, libertarian policy is very internationalist (without being interventionist). It would be hard to find people who advocate the unrestrained movement of goods, capital and people across international borders more enthusiastically than libertarians do. But when the U.S. government intervenes in the affairs of other nations by imposing economic sanctions or taking military action, libertarians get nervous.

The recent half-century of American global involvement coincides with the anomalous period of the Cold War. It was a time in which we faced a superpower rival that had both global aspirations and capabilities. The United States intervened worldwide to stem Soviet gains. But that superpower rival has been replaced with a multitude of potentially hostile nations and terrorist groups that may have access to weapons of mass destruction. With the end of the Cold War, the strategic environment has changed, but U.S. foreign policy has remained on autopilot.

The modern U.S. foreign policy establishment, whose views Mr. Rosenfeld represents, is quite comfortable with continued U.S. military interventions in places such as the Balkans and the Middle East. Mr. Rosenfeld calls them “investments in stability,” with costs that the American people find “manageable.” But the “stability” achieved by such interventions in those volatile regions is ephemeral at best. And it is doubtful that Americans would find a half-million casualties from a biological weapons attack on one of our cities “manageable.” Yet that is the risk we are incurring to pursue stakes that are marginal, or even irrelevant, to core American interests.

The U.S. foreign policy establishment regards the world as a chessboard and basks in the glory of America’s superpower status. This attitude is embodied in Mr. Rosenfeld’s rhetoric about “the core notion of community and American leadership.” But they refuse to acknowledge that the interventionist policies they favor sharply increase the risk of catastrophic terrorist attacks.

In contrast, the “live and let live” foreign policy of the nation’s Founders has never been more timely. In the new strategic environment, even the weakest players in the international system--terrorist groups--can inflict massive damage on a superpower.

Since the end of the Cold War, the rewards of intervention have decreased substantially, and the costs have increased exponentially. Today, an extended defense perimeter may well bring less security rather than more. We could reduce the chances of a catastrophic attack against the United States fairly painlessly by simply reserving the use of military force for those instances in which truly vital nationals interests are threatened.