Twenty-five years later, we haven't forgotten. And we haven't relaxed our vigilance against terrorism. We can't afford to do so now.
Twenty-five years after the September 11, 2001, terrorist attacks, the national outpouring of tears has mostly subsided. But the scars remain.
As scars do, they always will.
What has been learned in the years since?
America’s counterterrorism record is better than its Middle East policy — but the next threat may look nothing like the last one.
Part of the problem is, the United States still has not decided what it wants the Middle East to become.
We invaded Afghanistan, attempted to build a democratic government, negotiated with the Taliban and ultimately abandoned the government we had spent 20 years supporting. We removed Saddam Hussein without adequately preparing for the vacuum that followed. We have opposed Iran while occasionally making decisions that strengthened its proxies. American policy has oscillated between intervention and withdrawal, democracy promotion and unsentimental dealmaking.
Yet the United States has avoided another terrorist attack approaching the scale of 9/11.
Luckily for all of us, America learned the tactical lessons of 9/11 much better than it learned the strategic ones.
The country hardened airplane cockpits, federalized airport security and consolidated terrorism watchlists. The FBI shifted resources toward preventing attacks rather than merely investigating them afterward. Intelligence agencies became more willing — and legally able — to share information. American forces dismantled training camps, tracked financial networks and killed terrorist leaders.
The system has not worked perfectly. It has, however, made another elaborate operation involving 19 foreign hijackers much harder to organize.
The failed shoe-bombing attempt of December 2001 offered an early demonstration of the new reality. Richard Reid boarded a flight from Paris to Miami with explosives hidden in his shoes. His device failed to detonate properly, and passengers and crew subdued him.
Luck mattered. But passenger behavior had changed permanently. Before 9/11, travelers were taught to cooperate with hijackers who presumably wanted hostages or transportation. After United Flight 93, passengers understood that surrender might allow terrorists to turn an airplane into a weapon. Reid was not confronting a passive cabin. He was confronting people who knew they might have to fight for their lives.
The 2006 liquid-explosives conspiracy demonstrated another development. British authorities uncovered a sophisticated plan to smuggle bomb components aboard transatlantic flights and assemble the devices in the air. The plotters reportedly contemplated attacking several aircraft traveling from Britain to North America.
This time, the devices did not merely malfunction. Intelligence and police work disrupted the conspiracy before the attacks began. The restrictions on liquids that still irritate airline passengers resulted from authorities discovering a real plot exploiting a real vulnerability.
Those episodes illustrate how successful counterterrorism works. Authorities learn from one method, close the opening and force the enemy to search for another. Each additional layer of scrutiny increases the number of people who must avoid notice and the chances that somebody will make a mistake.
But success carries its own danger. We may become so proficient at preventing another 9/11 that we fail to imagine an attack bearing no resemblance to it.
The post-9/11 security architecture was designed principally to find organizations moving money, instructions and trained operatives across borders. Today’s attacker may already be living in the United States, radicalized through encrypted conversations and supplied with instructions generated or translated by artificial intelligence. He may require neither an overseas training camp nor direct contact with a terrorist commander.
Commercial drones could attack a crowded event, power installation or military facility. Cyberattacks could disrupt hospitals or contaminate confidence in water systems. Synthetic biology may eventually allow small groups to cause damage once requiring a state laboratory. Artificial intelligence can help extremists research targets, create convincing false communications or search enormous quantities of public information for vulnerabilities.
Directed-energy technology suggests another frontier.
The U.S. government reportedly acquired and tested a concealable, backpack-size device producing pulsed radio-frequency energy. Some investigators believe it may help explain the neurological injuries known as Havana Syndrome.
If a potentially harmful energy device can be carried discreetly and powered without a conspicuous military platform, American diplomats and intelligence officers could be attacked without gunfire, an explosion or immediately obvious evidence. A hostile government might damage personnel while preserving plausible deniability. A terrorist organization obtaining a similar capability might target an embassy, military command center or public gathering.
Meanwhile, American interests abroad remain easier to reach than the homeland. Embassies, ships, bases and commercial facilities sit close to Iranian proxies and other armed movements. Terrorists may conclude that attacking an American target overseas produces many of the same propaganda benefits without penetrating the formidable defenses of the continental United States.
None of this means another mass attack is inevitable. Nor should every technological advance become an excuse for panic or unlimited surveillance. America’s openness remains a source of strength, and constitutional protections cannot become casualties of permanent emergency.
It does mean that the absence of another 9/11 should be understood as an achievement, not proof that the threat has disappeared.
America succeeded through harder targets, consolidated watchlists, intelligence sharing, relentless disruption, help from cooperative Muslim communities, terrorist mistakes and some luck. It built an enormously capable protective apparatus even while pursuing a frequently incoherent Middle Eastern policy.
Now that apparatus must adapt. The next attack may not arrive aboard a hijacked airliner. It may come through a drone, computer network or weapon we cannot see.
We have been successful — not invulnerable. Afghanistan demonstrated why those conditions are dangerously easy to confuse.
(Contributing writer, Brooke Bell)