Introduction: symposium on foreign intervention.

• Author: Coyne, Christopher J.

What is the appropriate role of the state in matters of national security and defense? When, if ever, is it appropriate for government to use military force to intervene in other societies? What are the benefits, costs, and limitations of foreign interventions? These and related issues have always been contentious among libertarians and classical liberals. This was abundantly evident in the run-up to and subsequent invasions of Afghanistan and Iraq following the attacks in the United States on September 11, 2011. Some were staunchly against both interventions, whereas others were strongly in favor. Still others supported intervention in Afghanistan but not in Iraq. And even among those who considered themselves supporters of the invasion by the U.S. government, there was disagreement over the appropriate scope and scale of the military effort.

These disagreements did not end with Afghanistan and Iraq. Today there is a lack of consensus among libertarians and classical liberals over a range of foreign-policy issues, including but not limited to the appropriate role of the national security state at home and abroad, humanitarian intervention, nuclear agreements, and the U.S. government's drone program. The five papers in this symposium engage various aspects of foreign intervention and illustrate some of the tensions and open issues associated with libertarian and classical liberal perspectives on foreign policy.

Christopher Preble begins the symposium with an exploration of the roots of libertarian attitudes toward foreign policy in the United States. He discusses how America's Founders recognized the threats to domestic liberty posed by a standing military and therefore created a series of checks in the hopes of minimizing these risks. Attitudes regarding a standing army shifted after World War II, a shift that was coupled with a broader interpretation of what constituted the "common defense" as expressed in the U.S. Constitution. Preble closes with a discussion of the tensions and limits of an activist foreign policy and why a skepticism toward this policy is relevant today.

Fernando Teson makes a moral argument for armed intervention in order to combat and destroy the Islamic State of Iraq and Syria (ISIS). He argues that a war against ISIS, undertaken by an international military coalition, is just on the grounds of national self-defense, collective self-defense, and humanitarian intervention. Following the defeat of ISIS, he argues...