In the United States, national security often determines which issues, countries and programs receive the most attention from policymakers. As the U.S. Army War College teaches its up-and-coming leaders, “U.S. national interests determine our involvement in the rest of the world.” But despite the clear importance we place on national security, people rarely clarify or agree on what exactly “national security” entails. Does it just mean keeping the physical American homeland safe? Or is it broad enough to include the ability to pursue ideological goals, such as the promotion of democracy abroad?

National security is defined in many different ways, even by various organizations within the U.S. government. However, most definitions converge around the protection of a few key ideas:

1.     Physical security of the American homeland, as well as its citizens and assets abroad;

2.     Economic prosperity and the free movement of goods and services;

3.     Preservation and promotion of national values at home and abroad, including values like democracy, human rights, and the rule of law.

Yet even this definition leaves room for interpretation. While the majority of Americans agree that a terrorist attack in Ohio or an invasion of Idaho by the Canadian Mounties would fall under the umbrella of national security, other scenarios involving humanitarian crises and instability in remote developing countries are still fiercely debated.