While the international community generally considers mass migrant population flows across nation-states a primarily humanitarian crisis, Aaron Petty argues that it is often an intentional tool of aggression used by nation-states. The weaponization of migrants is the instrumentalization of population flows through both the threat and the actual migration of people into the territory of a target state. Use of migrants as a weapons system has a long history of being employed by nation-states as an act of aggression to obtain strategic foreign policy objectives.

In this article, Petty suggests that the weaponization of migrants is likely to increase against the United States and its allies, particularly where the current geopolitical environment of strategic competition between large powers is playing out below the level of armed conflict. Petty argues that weaponization of migrants could be deemed a violation of international law relating to armed conflict, and the United States should advocate that such tactics are not legally permissible and may justify legitimate retaliation to deter such weaponization.