September 10, 2021

CNAS Responds: American Security, Two Decades After 9/11

The exit from Afghanistan bookends two decades in which American security and foreign policy transformed both domestically and abroad. On the 20th anniversary of the September 11th attacks, CNAS experts reflect on what transpired in the years since and where U.S. foreign policy goes from here.

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  • Richard Fontaine, Chief Executive Officer: "On 9/11, I watched from my Pentagon City apartment as the flames grew and the smoke billowed. At a medical facility across the street, I then waited to help with a flood of patients. They never arrived, since most in the Pentagon were killed in the blast or escaped injury. The sight of thousands running from that conflagration hasn’t much faded over the years, and I suspect it never will.The fear that so motivated America’s response to 9/11 has waned, however, and that allows for a cooler appraisal of U.S. policy. It’s clear that there were huge successes: preventing another mass-casualty attack on the homeland, especially, and reorganizing the government to deal with terrorist threats. But there were also terrible overreaches, ranging from detainee torture to the war in Iraq. Balance has so often been the missing element in America’s post-9/11 foreign policy. In Afghanistan, which was neglected, then occupied, then subject to a surge, then withdrawal, and now the Taliban rules the country just like before. In Iraq: the United States was in, out, and then back. China was a pre-9/11 focus, quickly became a secondary consideration, and now is the overwhelming preoccupation of U.S. policy. Terrorism: a global war against it, then a retrenchment, and now resurgent worries about al Qaeda and ISIS safe havens. It should be clear after two decades that the United States is a global power, not a regional one; that it can’t focus overwhelmingly on one issue to the detriment of many others; and that it can mitigate but not solve many national security problems. Balancing our interests, values, presence, engagement, and efforts, on multiple issues in multiple places, should be the watchword of our new era."
  • Carrie Cordero, Robert M. Gates Senior Fellow: "On this 20th anniversary of the 9/11 attacks, we remember those who were innocent victims, first responders who selflessly risked their lives by running into toxic rubble, members of the armed forces who served at great cost in the long war, and all of their families whose lives were permanently altered by the attacks themselves and the government mobilization that followed. We also remember many behind the scenes in the intelligence and law enforcement communities, and among our allies and partners who made great sacrifices to keep the country safe over the past two decades from another attack on this scale. For the national and homeland security policy community, however, this anniversary should serve as a reminder to stay ahead of the threat. That means ensuring that our laws, institutions, and people are positioned to be able to adapt to a complex and evolving set of threats to security, safety, and public health. The 9/11 Commission report observed that “the World War II generation rose to the challenges of the 1940s and 1950s.” It urged the 9/11 generation to restructure the government to protect the country to meet the threat of two decades ago. Today, we face an array of threats here at home, including but not limited to, global pandemic, deadly, climate change-induced storms, domestic and international terrorism, malign foreign cyber activity, and a toxic disinformation environment. In our present moment, large-scale restructuring of the government is likely not the answer. The challenge for today’s national and homeland security community is to tap a new level of creativity to find what is."
  • Paul Scharre, Vice President and Director of Studies: "Twenty years after 9/11, the United States inhabits a very different strategic landscape. While nation building in Iraq and Afghanistan were costly failures, U.S. counterterrorism campaigns have been extremely effective. Early efforts to address the threat of terrorist safe havens through large-scale stability operations proved both unsuccessful and unwarranted. Through a combination of increased homeland security measures, intelligence collection, and a light footprint military approach using drones and special operations forces, the United States has been able to severely degrade the capabilities of al Qaeda and other transnational terrorist organizations. The United States must keep the pressure on global terrorist threats, even as the U.S. pivots the bulk of its attention towards competing with China. Non-state threats have always been an uneasy fit for national security bureaucracies, and many institutions will be all too happy to focus their attention on more traditional threats from nation-states. Yet the United States will only be kept safe by continued vigilance and pressure on transnational terrorist organizations. The departure of U.S. troops from Afghanistan closes one chapter of America’s post-9/11 conflicts, but counterterrorism operations will, and must, continue."
  • Lisa Curtis, Senior Fellow and Director, Indo-Pacific Security: "The 20-year anniversary of the 9/11 attacks is a particularly somber one as the Taliban retakes power in the country from which al-Qaeda launched its war against the United States so many years ago. After tremendous investment of U.S. blood and treasure in Afghanistan, the Taliban has roared back to power, putting al Qaeda-linked leader Sirajuddin Haqqani in charge of the country’s security—a stark reminder that the U.S. war against terrorism is decidedly not over. As we reflect on the nearly 3,000 lives claimed in one day on U.S. soil, the Biden administration must recognize it cannot wash its hands of the country, where al-Qaeda is set to reemerge and rebuild with the support of its Taliban allies. Unfortunately, the poorly negotiated and weak U.S.-Taliban agreement concluded during the Trump administration sealed the fate of a U.S. mission for which so many Americans have sacrificed. And contrary to President Biden’s assertions, Afghanistan continues to pose a threat to U.S. vital national security interests. To restore U.S. credibility with allies and partners, the United States must shift its diplomatic focus in Afghanistan to working with like-minded democratic partners on policies based on principles of freedom and human dignity, devise a military strategy to deal with reemerging terrorist threats, and stop wishing away the Taliban’s continued support for terrorism."
  • Ilan Goldenberg, Senior Fellow and Director, Middle East Security: "This 9/11 anniversary is an important moment to reflect on the successes and failures of the past 20 years. We know what has not worked—overthrowing government and pursuing counterinsurgency and nation-building campaigns with U.S. forces in the lead. However, we also have examples of successes where a combination of greater investments in intelligence, a more robust homeland security apparatus, and small deployments of U.S. forces to support local partners and manage crises instead of solving them have been effective. What the United States must do going forward is combine these lessons to develop a sustainable, cheaper model to manage, instead of solve, the challenges posed by terrorism and keep Americans safe. This would allow policymakers to finally shift their focus to more important issues such as great-power competition with China and transnational challenges such as climate change."
  • Katherine Kuzminski, Senior Fellow and Director, Military, Veterans, and Society: "The tragic events of 9/11 moved an entire generation of young professionals to serve the nation. The somber moment crystallized a calling for many, whether in uniform or as civilians in the national security enterprise. The events of the day—and the subsequent wars in Iraq and Afghanistan—shifted Americans’ concept of national security from the realm of Washington elites to an issue affecting all Americans. The contributions of the post-9/11 generation of civil servants and service members further expanded the conception of which departments and agencies contributed to national security, including not only the Department of Defense but also the State Department, USAID, the intelligence community, and the Department of Homeland Security. The memory of the day’s events is a reminder of the profoundly human weight of ensuring the nation’s security and the imperative to serve."
  • Jacob Stokes, Fellow, Indo-Pacific Security: "The 20-year period since September 11 has often been labeled the “post-9/11 era.” But that conceptual frame elides the most important geopolitical event of the century so far: the rise of the People’s Republic of China. Measured in current U.S. dollars, China’s annual GDP has grown from $1.3 trillion in 2001 to $14.7 trillion in 2020. Beijing’s military, the People’s Liberation Army, has similarly carried out a program of rapid modernization over the last two decades, and is now second only to the U.S. military. Those changes in absolute and relative material power—enabled, in part, by the U.S. focus on fighting terrorism in Iraq, Afghanistan, and elsewhere—have emboldened Chinese leaders to push forward toward their goal of becoming the preeminent power in Asia. Getting the next 20 years and beyond right will depend on how effectively American policymakers, along with allies and partners, respond now to the challenges that arose while they were occupied with trying to vanquish terrorism."
  • Becca Wasser, Fellow, Defense: "In the last two decades, the U.S. military approach to counterterrorism has shifted from large conventional operations that proved costly and unsuccessful, to a light footprint approach that leverages unmanned aerial systems, robust intelligence networks, and a mix of U.S. special operations forces and partner forces to degrade terrorist networks. Such efforts were honed in Afghanistan, practiced in locations like Somalia and Yemen, and further perfected during the fight against the Islamic State in Iraq and Syria. This approach has not only proven effective at degrading terrorist threats, but has also reduced the risk to U.S. military forces. What does remain the same is the core national interest of protecting the U.S. homeland. Even as the U.S. military focuses on preparing for great-power war against state adversaries, it must continue to train for counterterrorism operations and further refine its approach to counterterrorism in order to degrade terrorist threats against the United States."
  • Jason Bartlett, Research Assistant, Energy, Economics, and Security: "I was one of the 'lucky kids from Long Island, New York, as my mother was able to pick me up from school while several of my classmates became orphans in an instant on 9/11. Even at the age of eight, I knew that the world had fundamentally changed after hearing the words 'national security threat' for the first time. 20 years later, I'm analyzing U.S. economic measures and sanctions policies created to prevent another 9/11-like attack from ever happening again on U.S. soil. Although lacking a country-specific sanctions program, the Treasury has issued a wide array of economic sanctions spanning two decades related to Afghanistan—an accurate depiction of how U.S. economic coercion measures, especially sanctions, have drastically evolved after the 9/11 attacks. The fall of Kabul signifies the urgency of shoring up relations with our allies and applying the lessons learned from the Biden administration's general sanctions review to ensure the safety of our citizens and allies abroad."
  • Nathalie Grogan, Research Assistant, Military, Veterans, and Society: "

    Twenty years after September 11, the relationship between the military and broader American society is strained. The longest wars in American history were shouldered by less than 1 percent of the population, resulting in limited interactions between those fighting the war and those civilians at home. In addition to the lack of personal connections between the military community and the civilian public, American society was largely exempt from the fiscal consequences of war, as tax policies were developed separately from the war effort. The end of the war in Afghanistan marks a somber moment to reflect on the state of the civil-military relationship over the past 20 years. For a relationship that is necessary to the health of American democracy, it is vital to improve the interactions between the military and broader society."

  • James Frey, Senior Military Fellow: "Over the past two decades, an important aspect of U.S. foreign policy that has evolved is the use of unmanned aerial systems, or drones. In 2001, drones were solely employed for tactical intelligence surveillance and reconnaissance and had only nascent strike capability. Since then, drones have matured into operational systems with strategic impacts as precise instruments of warfare with the capability to strike nearly anywhere with limited or no risk to the force. This was recently demonstrated during reprisal drone strikes on ISIS-K during the Kabul evacuation. Other nations have followed, and unmanned systems on both large and small scales will continue to challenge, and change, the conduct of warfare and our previous assurances of air supremacy."
  • Christian Beckner, Adjunct Senior Fellow: "The 20th anniversary of 9/11 is first and foremost a time to remember and mourn those who lost their lives on that day, but also an occasion to reexamine the risks to our nation and our capabilities to anticipate and respond to them. While the foreign terrorist threat to the United States is persistent, and might now grow following the withdrawal from Afghanistan, we cannot also ignore the other threats that we face, from cyber attackers, domestic extremists, peddlers of disinformation, and deadly microbes. And we must, at the same time, also focus on the broad societal risks posed by climate change, economic dislocation, and civic disengagement and polarization. Addressing this panoply of challenges will require national security agencies to become much more agile and focused in assessing risks, setting priorities, conducting operations, and engaging on a whole-of-nation basis to protect and preserve our democracy."
  • Josh Campbell, Adjunct Senior Fellow: "Two decades after one of the most catastrophic intelligence failures in U.S. history, American security officials are now adapting to a new reality that includes fewer intelligence collection capabilities in the very part of the world that produced the 9/11 attacks. While smart voices debate the merits of America’s withdrawal from Afghanistan, one clear lasting consequence of having fewer boots on the ground will be a greater reliance on signals intelligence platforms and so-called “over the horizon” defense assets to rapidly address threats emanating in the region. Looking ahead, the ultimate test of the withdrawal decision will be found in the U.S. government's ability to effectively detect and mitigate any new extremist plots before they once again make their way to America's shores."
  • Christopher Kolenda, Adjunct Senior Fellow: "The United States has a problem. Our military interventions are consistently turning into quagmires that damage our credibility, harm innocent people, and make us poorer and worse off. We do not know the common policy and strategy errors that are heightening the risk of fiascos. The 20th anniversary of the September 11 attacks should prompt reflection and urgency for reform. The Biden administration should appoint a blue-ribbon panel in the style of the 9/11 Commission to investigate the problem and develop recommendations for national security reform."
  • Jim Townsend, Adjunct Senior Fellow, Transatlantic Security: "The vicious attacks on 9/11 caused an angry and fearful America to lash out in a spasm of military and political actions that, 20 years later, have little to show for the great cost paid in lives and treasure. While the United States successfully intercepted or preempted further major attacks on American soil, in the heat of the moment it also made political decisions that conflicted with American values at home and launched military actions abroad with elusive results but at a human cost in the hundreds of thousands. We did this as a nation with our eyes wide open. As we tally up the costs of these policies today, future generations should see, as I did, the results of hubris, of blind, misleading optimism, uncritical thinking by decision makers with a limited understanding of the facts, and decision-making shaped by a small group of insiders driven more by ideology, politics, and fear of telling truth to power—and an inattentive American public. These flaws will be ever present; future generations now have the lessons of the past 20 years to avoid making the same mistakes when it is their turn."
  • Alex Zerden, Adjunct Senior Fellow, Energy, Economics, and Security: "9/11 ushered in a new era of financial warfare, where the United States and allies deployed a powerful economic and diplomatic toolkit against terrorist financiers, illicit financial networks, kleptocrats, and nation-states. These efforts increased the impact of economic sanctions and reshaped global standards on anti-money laundering and countering the financial of terrorism (AML/CFT) through legislation, regulation, and innovative public-private partnerships. However, the successful use of these capabilities generally, and sanctions in particular, creates the potential for misuse or overuse, thereby diminishing their effectiveness. Strengthening AML/CFT safeguards has made it more expensive, risky, and cumbersome for malign actors to move funds around the world, but also elicited criticism from civil society and industry about unintended economic consequences."


  • Richard Fontaine

    Chief Executive Officer

    Richard Fontaine is the Chief Executive Officer of CNAS. He served as President of CNAS from 2012–19 and as Senior Fellow from 2009–12. Prior to CNAS, he was foreign policy ad...

  • Carrie Cordero

    Robert M. Gates Senior Fellow

    Carrie Cordero is the Robert M. Gates Senior Fellow and General Counsel at CNAS. Her research and writing interests focus on homeland security and intelligence community overs...

  • Lisa Curtis

    Senior Fellow and Director, Indo-Pacific Security Program

    Lisa Curtis is a Senior Fellow and Director of the Indo-Pacific Security Program at CNAS. She is a foreign policy and national security expert with over 20 years of service in...

  • Paul Scharre

    Executive Vice President and Director of Studies

    Paul Scharre is the Executive Vice President and Director of Studies at CNAS. He is the award-winning author of Four Battlegrounds: Power in the Age of Artificial Intelligence...

  • Katherine L. Kuzminski

    Deputy Director of Studies, Director, Military, Veterans, and Society Program

    Katherine L. Kuzminski (formerly Kidder) is the Deputy Director of Studies, and the Director of the Military, Veterans, and Society (MVS) Program at CNAS. Her research special...

  • Nathalie Grogan

    Former Research Associate, Military, Veterans, and Society Program

    Nathalie Grogan is a former Research Associate for the Military, Veterans, and Society Program at CNAS. Her research focused on the National Guard and military families. Groga...

  • Alex Zerden

    Adjunct Senior Fellow, Energy, Economics, and Security Program, Founder, Capital Peak Strategies

    Alex Zerden is the founder of Capitol Peak Strategies, a risk advisory firm based in Washington, DC. Capitol Peak works with leading financial institutions, companies and orga...

  • Jim Townsend

    Adjunct Senior Fellow, Transatlantic Security Program

    James Joye Townsend Jr. is an adjunct senior fellow in the CNAS Transatlantic Security Program. After eight years as Deputy Assistant Secretary of Defense (DASD) for European ...

  • Ilan Goldenberg

    Former Senior Fellow and Director, Middle East Security Program

    Ilan Goldenberg is the former Senior Fellow and Director of the Middle East Security Program at the Center for a New American Security. He is a foreign policy and defense expe...

  • Jacob Stokes

    Senior Fellow, Indo-Pacific Security Program

    Jacob Stokes is a Senior Fellow for the Indo-Pacific Security Program at CNAS, where his work focuses on U.S.-China relations, Chinese foreign and military policy, East Asian ...

  • Jason Bartlett

    Former Research Associate, Energy, Economics, and Security Program

    Jason Bartlett is a former Research Associate for the Energy, Economics, and Security Program at CNAS. He analyzes developments and trends in sanctions policy and evasion tact...

  • Col James Frey

    Former Senior Military Fellow, United States Marine Corps

    Colonel James W. Frey is a Commandant’s Fellow at the Center for a New American Security (CNAS) in Washington, D.C. Col Jay Frey recently completed a four-year assignment wit...

  • Christian Beckner

    Adjunct Senior Fellow

    Christian Beckner is currently the senior director of retail technology and cybersecurity at the National Retail Federation. In this capacity, Beckner leads NRF’s CIO Council,...

  • Josh Campbell

    Adjunct Senior Fellow

    Josh Campbell is an adjunct senior fellow at the Center for a New American Security. His research interests include domestic and international security, terrorism, intelligenc...

  • Christopher D. Kolenda

    Adjunct Senior Fellow

    Christopher D. Kolenda, Adjunct Senior Fellow at the Center for a New American Security, is the Founder of the Strategic Leaders Academy and helps solo practitioners and small...