NEW YORK – This week marks the 20th anniversary of the September 11, 2001, terrorist attacks on the United States. On that day, 19 terrorists took control of four civilian aircraft, flew two into the towers of New York’s World Trade Center, struck the Pentagon with a third, and crashed the fourth in a Pennsylvania field after passengers physically prevented the terrorists from reaching their target, often thought to be the White House or another US government building in Washington, DC.

All the hijackers were from the Middle East, 15 from Saudi Arabia alone. All were trained in Afghanistan, and four at US flight schools, as part of an operation planned, organized, and carried out by al-Qaeda (the “base”), the terrorist group headed by Osama bin Laden. By the day’s end, 2,977 innocent men, women, and children had been killed, and more than 6,000 injured. Most were American, although citizens of more than a hundred other countries also lost their lives as well.

Many at the time feared that 9/11 had ushered in an era defined by global terrorism. And, to be sure, other al-Qaeda attacks followed, including the train bombings in Madrid in March 2004 and the attack on London’s transit system in July 2005. Moreover, terrorists claiming allegiance to the Islamic State (ISIS) killed 32 people at Brussels Airport in March 2016, and staged a series of smaller attacks (often using vehicles to mow down pedestrians). But neither the US nor any of its allies has experienced another attack on the scale of 9/11 – or one even close to it. It is therefore necessary to ask: Beyond the immediate costs, what difference did 9/11 make? How did history change, if at all, as a result?

Terrorism, Unplugged

There are many explanations for why terrorists have not succeeded in executing additional major attacks. With the US invasion of Afghanistan, al-Qaeda lost its sanctuary. Almost every government around the world has introduced new screening procedures that make it more difficult for would-be terrorists to gain access to airports and airplanes. Countries have dramatically increased their intelligence, police, and military capabilities devoted to minimizing risks and countering threats. Countries have also increased their cooperation with one another; counterterrorism is a rare domain where governments that often disagree are willing and able to work together to a considerable degree.

There is also now broad agreement on what constitutes terrorism – the use of armed force by individuals and groups against civilians for political purposes – and a degree of support for the principle that governments should not distinguish between terrorists and those who give them sanctuary and support. Mostly gone are the days when individuals and groups who killed on behalf of their cause were romanticized as freedom fighters.

This is not to say that terrorism has not continued to claim tens of thousands of lives each and every year, which it most surely has. But almost all the attacks have taken place in the Middle East, Africa, and South Asia as part of ongoing conflicts (mostly in Iraq, Syria, Afghanistan, Libya, Somalia, Nigeria, Pakistan, and Yemen) as opposed to an isolated 9/11-style attack against one of the major powers. Terrorism is increasingly localized and decentralized. It is also resilient: capturing or killing the head of a terrorist organization does not necessarily spell its end. Al-Qaeda, for example, survived the killing of bin Laden by US special operations forces in Pakistan nearly a decade after the 9/11 attack.

It thus comes as no surprise that terrorism continues, with no end in sight. Nor can the possibility of a new 9/11 be ruled out, even though the US government has recently stated that the “most urgent terrorism threat” the country faces is domestic. As the Provisional Irish Republican Army put it after its failed effort to assassinate British Prime Minister Margaret Thatcher in 1984, “Today we were unlucky, but remember we only have to be lucky once. You will have to be lucky always.” The danger is that the day will come when terrorists gain access to nuclear material or figure out how to manufacture and deliver a biological or chemical weapon, in which case terrorism could come to define the age. For now, though, it has not.

America, Unleashed

Nonetheless, 9/11 marked a historical turning point, with a profound impact on US foreign policy in the two decades since. Although the attacks did not usher in an era of global terrorism, they did usher in the so-called Global War on Terrorism, which profoundly affected what the US did in the world, how the world came to regard the US, and how many Americans came to see their country’s foreign policy.

The saga begins in Afghanistan. Shortly after the 9/11 attacks, the US gave the Taliban, then in control of Afghanistan’s government, a choice: either hand over the al-Qaeda leaders who were living in their country and responsible for planning the 9/11 attack, or put their rule at risk. When the Taliban refused to hand over the al-Qaeda leaders, US intelligence and military personnel collaborated with a loose confederation of Afghan tribes known as the Northern Alliance in overthrowing the Taliban. The US helped assemble a successor government that took control of most of the country.

That control, though, was never complete or unchallenged. Many individuals loyal to the Taliban and al-Qaeda escaped to neighboring Pakistan, where they gradually rebuilt their strength and resumed military operations against the government that had replaced them. The US for its part did not do enough to build an Afghan military, reduce corruption, or deny the Taliban a sanctuary in Pakistan. Instead, it increased its own presence and military operations in Afghanistan, essentially becoming a partner of the government in its civil war.

At its peak, the US effort in Afghanistan involved more than 100,000 of its soldiers. Over two decades, US operations cost more than $2 trillion, and more than 2,300 Americans, as well as tens of thousands of Afghans, lost their lives. The effort was at once both too much and not enough. While the US presence robbed the Afghan government of much of its legitimacy and generated opposition in the US, the Taliban proved to have more staying power than the US, which by 2020 had lost its will to continue a fight that promised only an open-ended stalemate.

The Global War on Terrorism also led the US to launch a war in Iraq. It is an open question whether President George W. Bush would have initiated the war had it not been for 9/11. Certainly, the attacks increased his inclination to signal to the world that the US was not, as President Richard Nixon put it during the Vietnam War, a “pitiful helpless giant.” It made some in the administration (particularly Vice President Dick Cheney) unwilling to take the risk that terrorists might gain control of weapons of mass destruction, which Iraqi leader Saddam Hussein was widely thought (incorrectly, it turned out) to possess. Still others wanted to spread democracy to Iraq, and from there to the entire Middle East, on the assumption that this was not just possible, but also that it would make the region far less likely to produce terrorists and support terrorism.

The war in Iraq, launched in March 2003, did not go as intended or predicted by the Bush administration and the many in Congress (including then-Senator Joe Biden) and around the country who supported it. The US was unprepared for much of what was to come. Initial military victories ousted the government but soon gave way to widespread violent turmoil and civil war. Decisions to disband the Iraqi military and exclude from government jobs many of the Iraqis who had been associated with the previous regime exacerbated an already chaotic situation. More fundamentally, Iraq, like Afghanistan, demonstrated the limits of what military force could accomplish at a reasonable cost and in a reasonable timespan.

In the end, the US was forced to increase its military presence to nearly 170,000 troops to sustain the embattled successor government in Baghdad. A degree of stability was achieved, but at an enormous cost. The US spent at least as much there as in Afghanistan, but at a much higher human cost: more than 4,000 American soldiers killed, many times that number wounded, and soaring suicide rates among US troops (both in Iraq and Afghanistan). And this total excludes private contractors and Iraqi casualties, for which estimates vary widely but which certainly total several hundred thousand.

The war in Iraq also weakened the US in other ways. There was never any evidence that Iraq was involved in the 9/11 attacks, and America’s reputation suffered further when its stated rationale for launching a war without UN support – to eliminate Saddam’s weapons of mass destruction – turned out to have no basis in reality. Images of US soldiers mistreating Iraqi prisoners further tarnished the country’s reputation. Moreover, an Iraq at war with itself meant that Iran emerged as the most powerful country in the region (or one of two if Israel is included). Since the war, Iran has increased its sway over Iraq, Syria, Yemen, and Lebanon.

Iraq and Afghanistan also proved to be major strategic distractions. While the US was heavily involved in the Middle East and South Asia, regions that lacked any great-power presence or economic dynamism, the geopolitical balance moved against the US in both Europe and East Asia thanks to the emergence of a more aggressive Russia and a more capable and assertive China. The Global War on Terrorism did not and could not provide a compass for how US foreign policy should approach renewed great-power rivalry.

The World, Unmoored

The wars fought in the wake of 9/11 also had significant domestic consequences for the US. They shook the confidence of a country that had emerged from the Cold War with a historically unprecedented preponderance of power and shattered the national unity that came to the surface in the immediate aftermath of the attacks. Moreover, their costs and failures stimulated opposition to a continuing, large US global role, giving rise to a new tendency toward isolationism. Likewise, the push for war, together with the 2007-09 global financial crisis and its economic fallout, powerfully undermined Americans’ faith in elites, stimulating the rise of populist sentiment that, among other things, helped pave the way for the presidency of Donald Trump. Today’s US is more divided than ever at home and increasingly disinclined to carry out the sort of active foreign policy that has been its hallmark since World War II’s end, and which has, on balance, greatly benefited Americans and many others.

In hindsight, we can now see that 9/11 was a harbinger of what was to come: less the globalization of terrorism than the terrors of globalization. The attacks conveyed the message that distance and borders count for little in a global age. Little stays local for long, whether terrorists born in the Middle East and trained in Afghanistan, or the effects of the global financial crisis that had its origins in American financial mismanagement. We are all living with a pandemic virus that has killed millions since emerging in central China in December 2019. The fires, droughts, floods, storms, and heat ravaging much of the world are the consequence of climate change, itself the cumulative effect of human activity that has concentrated unsustainable amounts of heat-trapping greenhouse gases into the atmosphere.

The era triggered by events in Afghanistan has now come full circle, marking its 20th anniversary with events in Afghanistan. Twenty years ago, the Taliban were quickly ousted from power; in recent weeks they have regained power just as quickly. It is too soon to know whether the Taliban will revert to their old ways, becoming once again enablers of terrorism, and whether terrorists everywhere will get a boost from their victory over the US and its allies. What we do know, however, is that terrorism will remain a feature of our world. It will not define the future, but it will remain a visible aspect of the globalization that already has.

Richard Haass, President of the Council on Foreign Relations, is the author, most recently, of The World: A Brief Introduction (Penguin Books, 2021).

Copyright: Project Syndicate, 2021.

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