In the 20 years since the 9/11 attack, U.S. counterterrorism policy has achieved some striking successes and suffered some horrific failures. On the positive side, jihadi organizations such as al Qaeda and the Islamic State (also known as ISIS) are now shadows of their former selves, and the United States has avoided another catastrophic, 9/11-scale attack. The worst fears, or even the more modest ones, of U.S. counterterrorism officials have not been realized. With terrorism less of an immediate concern, U.S. President Joe Biden has turned Washington’s focus toward China, climate change, and other issues—even withdrawing U.S. troops from Afghanistan as part of an effort to end the so-called forever wars.
At the same time, however, many of the United States’ more ambitious foreign policy efforts done in the name of counterterrorism since 9/11, such as effecting regime change in the Middle East and winning the goodwill of Muslims around the world, have failed and even backfired. Although al Qaeda and ISIS are far weaker than they were at their peak, they have persisted in the face of tremendous pressure, and their reach, albeit at times more ambitious than their grasp, has only grown since 2001. Today, other countries face potent terrorist threats, and al Qaeda, ISIS, and their various affiliates and allies remain active in civil wars around the world.
Instead of a decisive victory, the United States appears to have settled for something less ambitious: good enough. It recognizes that although jihadi terrorism may be impossible to fully and permanently eradicate—or the costs of trying to do so are simply too high—the threat can be reduced to the point where it kills relatively few Americans and no longer shapes daily life in the United States. As Washington has grown more skeptical of large-scale counterinsurgency operations designed to reshape whole societies, the most recent three administrations—Barack Obama’s, Donald Trump’s, and now Biden’s—have focused on keeping jihadi organizations weak and off balance. Through a mix of intelligence gathering, military operations, and homeland security efforts, they have mostly succeeded in keeping the fight “over there.” To a remarkable degree, the United States itself has been insulated from the threat. Jihadism remains alive and well abroad and is not going away anytime soon, but the current U.S. doctrine is a politically feasible and comparatively effective way of managing the issue. Good enough, it turns out, is good enough.
The severity of the threat posed by jihadi groups such as al Qaeda and ISIS depends on where you are. Data from the think tank New America indicate that 107 Americans have died in jihadi terrorist attacks on U.S. soil since 9/11, almost half of whom were killed at the Pulse nightclub in Orlando, Florida, in 2016 by Omar Mateen, who declared allegiance to ISIS during his rampage. Europe, by contrast, has suffered far more such violence. In one gruesome 2015 evening in Paris alone, ISIS suicide bombers and shooters killed 130 people in a coordinated series of attacks. Europe has also seen far more stabbings and other low-casualty attacks, in part because it has stricter gun laws. As ISIS’s strength has waned, however, attacks on both sides of the Atlantic have subsided. As of mid-July 2021, the United States had not endured a jihadi attack since December 2019, when a Saudi student linked to al Qaeda in the Arabian Peninsula killed three sailors at a U.S. Navy base in Florida. Europe has suffered fewer casualties than during the peak years of 2015 and 2016.
These numbers pale in comparison to those of Africa, the Middle East, and South Asia, where jihadi groups are far more active than they were before 9/11. Al Qaeda has a presence in, among other countries, Afghanistan, Algeria, Bangladesh, Egypt, India, Iran, Libya, Mali, Pakistan, Saudi Arabia, Somalia, Syria, Tunisia, Turkey, and Yemen. ISIS is present in most of those countries, plus Cameroon, Chad, Iraq, Mozambique, Nigeria, and Russia. Many of these countries suffer from civil wars in which jihadi groups are among the active participants. Hundreds of thousands have died in these conflicts.
One crucial factor keeping the United States safe is the American Muslim community. After 9/11, U.S. officials feared that the country was home to an angry Muslim population riddled with al Qaeda sympathizers and sleeper agents. In 2003, Robert Mueller, the director of the FBI, warned that the country’s “greatest threat is from al Qaeda cells in the United States that we have not yet been able to identify.” This fear turned out to have no basis in fact. Compared with European Muslims, American Muslims are well integrated into society. Indeed, their average educational and income levels are equivalent to or higher than those of non-Muslims. Although some have attempted to travel abroad to join ISIS, they have done so at far lower rates than European Muslims. Most important, American Muslims have cooperated closely with law enforcement and the FBI, making it hard for cells and radicalized individuals to organize and plan operations.
The jihadi movement also suffers from numerous weaknesses that hamper its ability to carry out attacks. Even at the height of al Qaeda’s power, for instance, the movement the group sought to lead had conflicting priorities: Should it fight foreign invaders, topple supposedly apostate regimes in the Middle East, or take the war to the United States? These divisions are more pronounced today. Different factions disagree on whether and when to declare an Islamic state, how to handle nonbelievers and the insufficiently pious, which enemy to target first, and, of course, who should be the overall leader of the movement. In Iraq, these disputes led some fellow jihadis to condemn al Qaeda, and in Syria, they led to a rift that gave rise to ISIS and a jihadi civil war.
The movement also lacks a sanctuary akin to what it enjoyed on the eve of 9/11. More than 10,000 volunteers traveled to Afghanistan when it was under the Taliban’s rule to train in camps run by al Qaeda and other militant organizations. This safe haven was a powerful unifying force that made al Qaeda more lethal. It allowed its leaders to bring jihadi groups and individuals together from across the globe, train them to fight, indoctrinate them into a common agenda, and give those with special language skills or particular promise additional training.
Today, the movement tries to make do with multiple smaller safe havens, but none has proved as effective a launching pad as pre-9/11 Afghanistan did. Al Qaeda, ISIS, their affiliates, and other jihadi groups are present in war zones around the Muslim world. In those wars, members of these organizations learn to use weapons and forge intense bonds with one another. But they engage primarily in civil war, not international terrorism. As a result, they do not receive the same training as previous generations of jihadis did—and local leaders often assign the most promising local recruits and foreign volunteers to important roles in local conflicts rather than give them international terrorist assignments. The vast majority of the over 40,000 foreign fighters who joined ISIS during the Syrian civil war, for instance, fought to defend the caliphate in Iraq and Syria, not to project terror abroad.
The United States and its allies, moreover, exert constant pressure on most local affiliates—often to the point where they reject their mother organizations. Consider al-Nusra Front, once al Qaeda’s affiliate in Syria, the most important war zone for the jihadi movement in the last decade. In 2016, it publicly distanced itself from al Qaeda. Al-Nusra’s leader, Abu Mohammad al-Julani, declared that he and his organization rejected attacks on the United States and Europe. For al Qaeda, this was a major military setback and an even larger reputational blow, threatening its status as the would-be leader of the broader jihadi movement.
Iran is another second-rate safe haven for al Qaeda. As the U.S. State Department noted in its 2020 annual report on terrorism, since 9/11, Tehran had “continued to permit an [al Qaeda] facilitation network to operate in Iran, sending money and fighters to conflict zones in Afghanistan and Syria, and it still allowed [al Qaeda] members to reside in the country.” Because Iran has an effective air defense system and Washington wants to avoid a broader conflict with Tehran, the United States does not carry out drone strikes or other direct attacks against al Qaeda figures there, giving them a degree of protection. But the group still must worry about other counterterrorism operations in the country. In 2020, Israeli assets—operating at the behest of the United States, according to interviews of intelligence officials conducted by The New York Times—killed Abu Muhammad al-Masri, a top al Qaeda official living in Iran.
The Iranian government itself also places numerous restrictions on al Qaeda figures in the country. Al Qaeda documents captured by U.S. forces revealed that some members of the group moved to Iran after 9/11 only out of desperation, and the organization’s relationship with the Iranian government has been marked by hostility and suspicion. For much of the post-9/11 period, al Qaeda members in Iran have often been considered captives or at least potential bargaining chips, not welcome guests. In addition, ties to Iran—a Shiite power that many religious Sunnis loathe—are unpopular among jihadis and discredit al Qaeda when publicized. ISIS, which is not based in Iran and supports attacks on the Islamic Republic, has criticized al Qaeda for its links to the country.
The U.S. withdrawal from Afghanistan could restore some of al Qaeda’s freedom of action in the country. As it did before 9/11, the Taliban might once again support or tolerate a large al Qaeda leadership presence and give the group free rein to train, plot, and recruit there. Alternatively, the Taliban may simply work with al Qaeda fighters against their mutual enemies in Afghanistan but discourage broader international terrorist operations. For now, it remains unclear which Afghan Taliban leaders support direct attacks against the United States. Even before 9/11, several staunch Taliban supporters did not appear to approve of such operations, even if they did little to stop them.
Moreover, the United States’ withdrawal from Afghanistan will not end its ability to affect the situation on the ground. Washington will retain diplomatic options, such as sanctions and multilateral pressure, to influence the Taliban’s behavior. The United States is also working on an array of basing and access arrangements that would allow the U.S. military to strike targets in Afghanistan and Pakistan after the withdrawal of all U.S. troops. Such arrangements will not fully replace a direct U.S. presence in Afghanistan, but they could make it difficult for al Qaeda to plot freely or run large-scale training camps in the country. In short, although the United States’ departure is unquestionably a victory for al Qaeda, it is not yet clear how big a win it will prove.
Beyond geographic safe havens, jihadis often use virtual sanctuaries. Even these, however, are less secure than they once were. Al Qaeda exploited the Internet for many years after 9/11, using email, chatrooms, and websites to communicate with followers, publicize the movement, and direct operations. ISIS put that approach on steroids, using platforms such as Facebook, Twitter, and YouTube to recruit widely and spread propaganda. When ISIS reemerged during the Syrian civil war, electrifying jihadi extremists worldwide with its beheading videos, Twitter hashtag hijackings, and other social media successes, it seemed that technology was on the terrorists’ side. Not so today: although jihadi groups remain active on mainstream platforms, the companies that control them now remove jihadi content and ban users who promote it. Many governments, for their part, now aggressively monitor terrorist-linked accounts to identify followers and disrupt potential plots. For the would-be terrorist, social media has become a risky place to reside.
After years of grand designs with ambitious goals, the United States has settled on a set of policies designed to weaken foreign jihadis while protecting the U.S. homeland. Perhaps the most important but least appreciated of these policies is the U.S.-led global intelligence campaign against terrorist groups. After 9/11, the United States developed or expanded security partnerships with more than 100 countries. Local intelligence agencies have the manpower, legal authority, language skills, and other vital resources to monitor, disrupt, and arrest suspected terrorists. Jihadis now find themselves hunted when they try to establish cells, recruit new members, raise money, or otherwise prepare for attacks. The discovery of a terrorist cell in one country, moreover, often leads to arrests in another if the jihadis try to communicate, share funds, or otherwise work together across borders. U.S. intelligence agencies, for their part, share relevant information, push partners to act on it, and, when these partners do, gain new information that continues the cycle.
Some governments, however, are too weak for such intelligence cooperation to function effectively. In such cases, the United States uses drone strikes and airstrikes, along with raids by special operations forces, to attack al Qaeda, ISIS, and associated groups. Washington usually conducts these operations with the approval of local governments, as it does in Pakistan, or by taking advantage of the lack of a functioning government, as it does in Somalia and Yemen. In addition to the al Qaeda leader Osama bin Laden, the United States and its allies have killed the al Qaeda in the Arabian Peninsula leader Nasir al-Wuhayshi, the leading English-language jihadi propagandists Anwar al-Awlaki and Adam Gadahn, and the South Asian al Qaeda leader Ilyas Kashmiri, as well as important operational figures, such as Rashid Rauf and Saleh al-Somali, both of whom orchestrated attacks in the West. Washington and its allies have also assassinated al Qaeda’s new leader in Yemen, Qasim al-Raymi; the leader of the group’s North African branch, Abdelmalek Droukdel; and the leader of its unofficial affiliate in Syria, who was known as Abu al-Qassam. The United States launched a similar campaign against ISIS, killing its self-proclaimed caliph, Abu Bakr al-Baghdadi, in 2019, among many other leaders.
Such efforts, of course, do not end terrorism, and they often kill innocent people caught in the crossfire. They are, however, effective at keeping jihadi groups weak. Decapitation strikes create constant churn within organizations, and many terrorist groups do not have a deep bench of would-be leaders, making it difficult for them to replace experienced commanders.
The constant fear of drone strikes and raids also undermines terrorist groups’ effectiveness—perhaps more than the death of individual leaders. Members cannot gather in significant numbers for fear of detection, making it hard to sustain large training camps. If groups communicate, they risk being tracked. Isolated and dispersed, terrorist groups then risk splintering into disparate cells that are difficult to coordinate. Cells may go against the wishes of senior leadership and even compete with one another. Without the ability to communicate, leaders also lose their relevance. When the Arab Spring protests, the most important event in the Arab world in a generation, began in late 2010, al Qaeda waited weeks before commenting. In contrast, rival voices across the Arab world offered their views constantly, particularly on social media. At the height of the Syrian civil war, Ayman al-Zawahiri, bin Laden’s successor as the leader of al Qaeda, went incommunicado for long stretches of time—prompting the al-Nusra Front leader Julani and other affiliated members to distance themselves from the core organization. For its part, ISIS has managed to remain more active, both on the battlefield and in its propaganda efforts. But it, too, is diminished. U.S. pressure has forced the group’s leaders into hiding, making it difficult for them to coordinate and direct global operations.
A separate set of U.S. efforts to track terrorists’ travel activities, share databases of suspects, and tighten borders has also made it harder for terrorists to penetrate the United States. After 9/11, the FBI undertook a far-reaching campaign to identify, disrupt, and arrest potential terrorists on U.S. soil—a campaign that continues unabated to this day. Many terrorist plots would have come to nothing regardless, but some might have reached fruition if not for government intervention. Alert citizens and law enforcement officers have caught other potential terrorists. The police foiled a plot to bomb military installations at Fort Dix in 2007, for example, when the jihadis went to a Circuit City store to transfer from a VHS tape to a DVD videos of themselves shooting weapons and shouting “Allahu akbar.” The employee making the transfer contacted law enforcement. Travel is also far harder for would-be jihadis than it was in decades past. Unlike in the 1990s, potential terrorists cannot travel to a sanctuary such as Afghanistan for training without a high risk of detection and arrest. As a result, many Western jihadis are untrained, making them far less dangerous.
To understand the cumulative effect of these counterterrorism measures, it is helpful to consider the problems al Qaeda or another jihadi group would face if it sought to carry out a spectacular terrorist attack similar to 9/11. Al Qaeda began planning that strike in late 1998 or early 1999 from bases in Afghanistan and Pakistan, where the group had deep networks and the support of local governments. After receiving approval from bin Laden, Khalid Sheikh Mohammed, an experienced senior jihadi and the overall architect of the attack, started recruiting members in 1999. Mohammed initially tried to draw heavily on veteran fighters, but their inexperience in the West made them poor candidates to lead the operation. Al Qaeda leaders instead identified Mohammed Atta, who had lived in Germany for several years, as an ideal cell leader. Commanders noticed Atta’s English fluency, religious fervor, and comfort operating in the West when he traveled to Afghanistan in 1999.
The hijackers prepared for the operation in Afghanistan, where some learned to hijack planes and disarm air marshals. A group of the planners held a meeting in Malaysia in January 2000, where U.S. intelligence picked up fragments of their trail, but not enough to detect the plot. The hijackers themselves began entering the United States that same year, although some first traveled to Germany. In California, two members with weaker English-language skills probably received some support from the local Muslim community via area mosques. Others prepared by taking flight lessons and going on practice runs—traveling first class cross-country on the type of aircraft they would later hijack. In the summer of 2001, Atta traveled to Spain to meet with Ramzi bin al-Shibh, one of the attack’s coordinators. There, Atta received further instructions and finalized plans for the attack. Money for expenses flowed through accounts in the United Arab Emirates. Throughout this planning process, al Qaeda enjoyed a crucial advantage in Europe and the United States: official neglect. Intelligence and law enforcement services in both places were focused on other priorities, allowing the jihadis considerable freedom of movement.
On September 11, 2001, the operation proceeded like clockwork—aided by an airport security system unaware that such an attack was possible. The hijackers boarded four planes without arousing suspicion. Although authorities selected some of the hijackers for extra scrutiny, that simply meant that their bags received a slightly more thorough screening. They likely carried utility knives or pocketknives permissible under the guidelines of the time, and several reports indicate that the hijackers also had Mace and box cutters, which the screeners may not have detected. After takeoff, the attackers forced their way into the planes’ cockpits and successfully turned three of the four airliners into massive suicide bombs, killing almost 3,000 people.
Every step of the way, a plot on the scale of 9/11 would be far harder to carry out today. With no sanctuary on a par with pre-2001 Afghanistan, volunteers have few training opportunities—and even fewer chances to plot direct attacks against the United States. Indeed, would-be terrorists risk arrest in their home countries and in transit. If they eventually made it to a war zone or other haven, they would also find it far harder to gather safely or communicate without being detected by local or foreign intelligence agencies. Authorities in the United States or elsewhere could capture senior figures who might give up important operational details. And leaders such as Khalid Sheikh Mohammed might be killed by a drone strike. Governments might detect meetings in other countries or funding flows through foreign banks—revealing not just the plot but also the identities of many other group members. If terrorists tried to recruit, raise money, or conduct operations via social media, the platforms’ moderators might ban them from the sites or report them to the FBI. Their social media followers might, in turn, come under suspicion. The visa applications of would-be flight students from the Middle East now receive far more scrutiny. If plotters managed to make it to the United States, a wary public and a cooperative Muslim community would be more likely to report suspicious activity. Al Qaeda could not tell its operatives to seek support from locals without the risk of detection. Even if terrorists managed to overcome all these obstacles, carrying out an actual attack would still be far harder: civil aviation and other sensitive targets are much better guarded than they were before 9/11.
No single measure by itself can make a repeat of a 9/11-scale plot impossible. But the cumulative effect of these policies and changes has made a sophisticated and high-impact scheme much less likely to succeed. It is not an accident that most attacks in the United States and even Europe in the last decade have been so-called lone-wolf incidents—inspired, rather than directed, by groups such as al Qaeda and ISIS. These kinds of attacks are usually less deadly, but they are harder to stop.
With the risk of 9/11-scale violence significantly reduced, it is tempting to declare victory and return to the pre-2001 level of vigilance. This would be a mistake. The United States has failed in many of its more ambitious attempts to fight jihadi groups, suggesting that terrorism will remain a threat for years to come. Although the danger these groups pose will remain manageable, preventing attacks will still require ongoing counterterrorism efforts.
The need for continued vigilance stems in part from Washington’s failure to win over the Muslim world. After 9/11, U.S. leaders sought to cultivate goodwill among Muslims through advertising campaigns; new broadcasting entities, such as the Arabic-language station Radio Sawa and the television channel Al Hurra; and, eventually, social media initiatives. But polling data suggest that these efforts have had little impact. Public opinion of the United States in the Arab world is still largely negative, although it has varied somewhat over the years. In 2015, over 80 percent of poll respondents in Jordan—a close U.S. ally—had an unfavorable opinion of the United States. This is damning, but it should not come as a surprise. Unpopular U.S. policies, such as the 2003 invasion of Iraq, which many throughout the Muslim world opposed, and U.S. support for Israel, have overshadowed fine-tuned messages about how wonderful life in the United States is for Muslims. As a result, anti-American groups continue to find it easy to recruit followers, and the incentive for targeting the United States remains high.
Jihadi-linked insurgencies are also far more prevalent now than they were before 9/11. This is partly because of the collapse of governments throughout Africa and the Middle East and partly because of the weakness of many surviving regimes. It takes only a small band of fighters to establish an insurgency in a weak state such as Mozambique and even fewer in a failed state such as Yemen. The jihadi cause, moreover, offers local fighters a compelling brand, enabling them to sell their movements to the community as providers of law and order and defenders of the faith. With jihadi bona fides, they can also tap into transnational networks, gain support from like-minded fighters in neighboring states, and, at times, acquire resources such as money, weapons, and access to propaganda.
In the past, the United States turned to counterinsurgency to combat these groups—deploying tens of thousands of its own forces to fight the Taliban in Afghanistan and various Sunni jihadi groups in Iraq. With public support for such efforts declining, however, and jihadi groups spreading to more countries, the U.S. military and intelligence agencies now often resort to training and equipping local forces that can act as the tip of the counterterrorism spear. Such U.S. proxies have battled al Shabab in Somalia, an ISIS offshoot in Libya, and al Qaeda–linked Abu Sayyaf in the Philippines, among other groups.
In a few places, the United States has managed to make headway against jihadis by partnering with local government forces. In many others, however, the defeat of one jihadi group has simply made room for the emergence of another. After 9/11, U.S. forces helped the government of the Philippines rout Abu Sayyaf; today, the Philippines is fighting an ISIS-linked organization. Elsewhere, even that limited level of success is elusive. The enormous amount of money, time, and equipment the United States poured into helping anti-ISIS fighters in Syria and the governments of Afghanistan and Iraq appears to have achieved, at best, only modest results. Training successes are limited to some small elite units such as Iraq’s Counterterrorism Service. Efforts to stand up large armies have largely failed.
U.S. attempts to improve the quality of governance in states with jihadi terrorist problems have an equally mixed legacy. Some countries, such as Yemen, have slipped into civil war, while corruption, poor economic growth, and undemocratic political systems plague many others, such as Egypt and Pakistan. Where progress toward democratization has occurred, such as in Indonesia and Tunisia, it was the work of indigenous movements and leaders, not U.S.-led efforts.
Counterterrorism policies within the United States suffer from a different set of problems. Politicians should level with the American people about the real risk of terrorism—which is low compared with many other dangers—as a way of inoculating the public against the psychological effect of small attacks. Despite 20 years of limited terrorist violence in the United States, however, polls show that the number of Americans “very” or “somewhat” concerned about terrorism remains high and has even grown in recent years. Political leaders continue to use this fear as a cudgel, criticizing one another when attacks occur and using these rare incidents to advance particular agendas on issues such as immigration. When Umar Farouk Abdulmutallab, an operative for al Qaeda in the Arabian Peninsula, almost blew up a plane over Detroit in 2009, Republicans blasted Obama for this near failure. As a candidate and in office, Trump used the asylum status of the 2013 Boston Marathon bombers to bolster his calls for a border wall, among other anti-immigrant measures.
As a result, the U.S. legal system and public discourse often single out American Muslims as a potential threat. Many Americans now associate Islam with violence, even though very few American Muslims have been involved in terrorist activities, and even though the larger American Muslim community has proved willing to work with U.S. law enforcement. In 2020, Muslims reported the highest level of discrimination of any religious group in the United States. Many American Muslims worry that the police do not treat them equally. This state of affairs is both unjust and counterproductive. If community members fear law enforcement, they may not seek out the authorities if a problem arises.
Twenty years after 9/11, U.S. policy is stuck—but not necessarily in a bad way. The mix of intelligence cooperation, military pressure on groups in their havens, and better homeland security has largely insulated the United States from terrorist violence. Still, Washington has failed to permanently solve the problem. Today, the United States is still bombing and raiding the ideological descendants of the original 9/11 planners. There is no end in sight, and groups such as al Qaeda remain committed to attacking the United States. Even so, constant pressure keeps these organizations weak, and as a result, they will conduct fewer and less lethal attacks. Jihadi terrorism will not go away, but its biggest impact is felt mainly in parts of the world where U.S. interests are limited. Washington must therefore think hard about where to deploy its counterterrorism resources. Although violence in Chad or Yemen is catastrophic for those countries, its impact on U.S. security is small. Efforts to promote democracy or improve governance may be valuable for other reasons, but they are unnecessary for heading off potential terrorist threats. In some cases, such efforts may actually make the situation worse.
The United States also needs to do more to manage the domestic politics of counterterrorism. Public fear keeps support for robust defense programs strong, but it also makes it easier for terrorists to gain attention and sow panic. Politicians must therefore tread cautiously in the aftermath of terrorist attacks and condemn extreme reactions of all kinds. When (not if) the next attack occurs, it will be vital for the president and other leaders to react responsibly. They must not only stress the need to help the victims and punish the killers but also explain that such events are rare and that the American Muslim community is part of the solution, not the problem. Local leaders, including police officials, should reach out to their Muslim communities to show support and guard against any retaliatory violence. Unfortunately, the last 20 years have shown that politicians will reliably exploit fear, even when the actual threat is limited. Such behavior only helps terrorist groups as they strive to stay relevant.
Israeli officials have a useful phrase to describe their own good-enough counterterrorism strategy: “mowing the grass.” The idea is that by conducting regular raids against terrorists and continually gathering intelligence, the government can keep terrorist groups such as Hamas weak, even if those groups’ attacks will always continue. The goal is to manage, rather than eliminate, the terrorist threat, and this frees the government to focus on other concerns. Having found a similarly imperfect but largely effective solution to the problem of jihadi violence, Washington should do just that, prioritizing China, Russia, climate change, and other pressing issues. With its post-9/11 counterterrorism toolkit, the United States can keep terrorist groups in remote countries weaker and off balance while accepting that at least some threat will always remain.