In the 17 years since the attacks of Sept. 11, 2001, U.S. law enforcement has prevented another large-scale terrorist attack on the homeland. The militaries of the United States and its allies have relentlessly pursued terrorists overseas, killing Osama bin Laden and dismantling the Islamic State.

Despite these achievements, the global struggle against extremism is not over. In the past five years, over 150,000 people have been killed in terrorist attacks, six times the number killed in the five years following Sept. 11. Since 2001, attacks worldwide have increased fivefold. From the Sahara Desert to cyberspace, Islamist militants continue to find innovative new ways to extend their reach. They have established a presence in more places than ever before and govern territory in close to a dozen countries across the Middle East and Africa.

Fourteen years after the 9/11 Commission that I chaired issued its final report, Congress has tasked the U.S. Institute of Peace with developing a plan to “prevent the underlying causes of extremism” in fragile states in the Sahel region of central Africa, the Horn of Africa and the Middle East. I, along with the former U.S. Representative Lee Hamilton, the vice chair of the commission, have agreed to lead this effort to fulfill the one unmet recommendation of the 9/11 Commission: to prevent the continued growth of Islamist terrorism.

Preventing the spread of terrorism requires a realization that terrorists cannot be defeated only by force.

Preventing the further spread of terrorism requires a realization that terrorists cannot be defeated only by force. Rather, the United States needs a preventive strategy to mitigate the political, economic and social causes of extremism. This strategy contains five essential elements.

First, the United States needs to reorient current spending toward programs that address the underlying causes of extremism. The United States has already spent close to $6 trillion fighting terrorism, the vast majority on military and law enforcement operations. The calls in the initial 9/11 Commission Report to confront the growth of extremism by expanding educational opportunities, fostering economic development and encouraging more open, tolerant societies have gone unheeded. Even in countries where extremists have established a presence, an overwhelming percentage of U.S. development spending goes to public health and disaster relief rather than programs that engage vulnerable youth, promote women’s leadership or empower civil society.

Second, the United States should prioritize targeted, locally owned programming, which shows promise in dissuading individuals from joining terrorist groups. In 2010, a U.S.-funded program in eastern Afghanistan recruited upstanding young men and gave them training and funding to design and implement projects that they—rather than foreign technocrats—thought would improve their community, like building dams or terraces. In areas where this program was implemented, insurgent strikes plummeted, even as attacks spiked across the rest of Afghanistan. In Somalia, another U.S.-funded effort to provide secondary education and opportunities for civic engagement to vulnerable youth caused support for and participation in political violence to plummet by as much as 50 percent.

The U.S. should prioritize targeted, locally owned programming, which shows promise in dissuading individuals from joining terrorist groups.

Third, the United States needs to reform the way it delivers and implements foreign assistance. Current U.S. assistance toward fragile states does not prioritize the right programs and is heavily earmarked, poorly monitored and fragmented. Security assistance to enhance the capacity of repressive, exclusionary regimes to commit violence is often prioritized over longer-term efforts to foster more meaningful reforms that can build peace. Changes to the federal bureaucracy are needed to better enable the United States to set priorities, commit to more predictable funding and hold both itself and fragile state partners accountable for progress.

Fourth, the United States needs to better leverage the efforts of other donors. Geographic proximity and the migration crisis have caused European countries to commit billions to confront extremism in the Sahel. The Gulf States, too, are becoming increasingly active in efforts to curb extremism. Nevertheless, existing global efforts remain poorly coordinated and rarely follow best practices. The United States should become more active in global efforts to unite donors and recipients around a common agenda.

Fifth and finally, the United States needs to act with decisive leadership in a time of rising geopolitical uncertainty. Major global and regional powers such as China, Russia, the Gulf States, Turkey and Iran are more active in the region than ever before, and growing strategic competition among them is a major cause of the recent rise in extremism. High-level diplomacy is needed to mitigate the potential for further outbreaks of conflict that extremists will exploit.

Implementing this preventive strategy will be hard. There will be setbacks, and, by definition, a strategy designed for the long haul will take some time to bear fruit. But after 17 years of an approach that has created more terrorists than it has killed, the United States can ill afford to wait.

This article appears in January 21 2019.