The absence of the United States in world affairs following World War I left Europe in the political disarray that led to World War II, said historian Robert Kagan last week at the first 2014 Protect America Month event at The Heritage Foundation.

Kagan addressed the peril of isolationism, not only to the U.S., but also to its allies. Sustaining world order depends upon the U.S. and its military power, he said.

The world wants U.S. involvement, Kagan argued. Ukraine’s fearful neighbors want U.S. troops to defend them against Russian aggression. Allies in Asia want guarantees of support against China. But America’s foreign policy is on the path of failure. Pivoting and resetting have left U.S. allies unsure of its commitment to international security. Meanwhile, the Department of Defense is forced to make program cuts that hamper its ability to achieve defense objectives.

Kagan called out the ordinary citizen as well as the national government. Americans must think outside their own interests. Congress is able to cut the defense budget because Americans don’t care:

We are not unable to spend the money necessary, both to build up our defense capacities, which is critical, but also to provide critical assistance when necessary to shore up the international order. We have convinced ourselves that we don’t have the money because we’ve chosen not to prioritize.

The world order won’t sustain itself, Kagan warned. If the United States pulls back, chaos will ensue.

The Founders emphasized national security when they named providing for the common defense one of the core responsibilities of the federal government. The security challenges America faces today are different in form but not in character than they were back then. Freedom is still under attack.

The next Protect America Month event is NDAA and the Future of U.S. National Security featuring House Armed Services Committee chairman Buck McKeon (R–CA) on May 6.

To view previous Protect America Month events and research, click here.

Amanda Hall is currently a member of the Young Leaders Program at The Heritage Foundation. For more information on interning at Heritage, please click here.