Foreign fighters cascade from one conflict to the next. Since September 11, 2001, the United States has confronted the phenomenon of foreign fighters in Afghanistan, Pakistan, Iraq, the Philippines, Yemen, Libya, and Syria—to name a few. As those who fought in Iraq and Syria move on to new conflicts, that list of countries may grow.
Over the last 16 years, the United States military and intelligence communities have honed and deployed a ruthlessly efficient counter-network capability to remove key individuals from the field.
Long hallmarks of U.S. counterterrorism, counter-network operations, and kinetic strikes are politically appealing because they are measurable, visible, and capitalize on sophisticated intelligence and precision strike capabilities.
However, trends among foreign fighters may blunt the United States’ comparative advantage in killing key terrorism leaders. First, the fighting in Iraq and Syria has further democratized the foreign fighter movement and made for an ever-replenishing list of high-value targets. Second, foreign fighters (and terrorists in general) may be moving from active armed conflict areas to urban centers. The first factor threatens to exhaust U.S. counterterrorism capabilities and the second threatens to decrease its overall significance.
If the United States intends to play an enduring and central role in reducing the impact of foreign fighters, it should endeavor to pay greater attention to the less quantifiable, “squishier,” goals of sharing and integrating information, as well as building resiliency among countries that face the threat.
In performing the type of predictive “heat mapping” analysis to suggest where fighters are likely to migrate, this report risks being tactically tautological: criminality and terrorism occur where there are criminals and terrorists. The value may instead be found in suggesting where migrating foreign fighters might create venues for future geopolitical competition or challenges to U.S. influence. By anticipating these potential challenges, the United States can help allied states build capacity to disaggregate militant entrepreneurs from vulnerable populations, and channel competitors’ concern over foreign fighters in a productive, mutually beneficial manner.