It was a decade ago that 19 terrorists took control of four planes, flew two into the twin towers of the World Trade Center, hit the Pentagon with a third, and crashed the fourth in a field in Pennsylvania after passengers resisted and made it impossible for the terrorists to complete their malevolent mission. In a matter of hours, more than 3,000 innocent people, mostly US citizens, but also people from 115 other countries, had their lives suddenly and violently taken from them.

Doug Kanter/AFP

As for the future, it is much more likely to be defined by the US’ need to put its economic house in order; China’s trajectory within and beyond its borders; and the ability of the world’s governments to cooperate on restoring economic growth, stemming the spread of nuclear weapons, and meeting energy and environmental challenges.

It is and would be wrong to make opposition to terrorism the centrepiece of what responsible governments do in the world. Terrorists continue to be outliers with limited appeal at best. They can destroy, but not create. It is worth noting that the people who went into the streets of Cairo and Damascus calling for change were not shouting the slogans of Al Qaeda or supporting its agenda.

Moreover, measures have been implemented to push back, successfully, terrorists. Intelligence assets have been redirected. Borders have been made more secure and societies more resilient. International cooperation has increased markedly, in part because governments that cannot agree on many things can agree on the need to cooperate in this area.

Military force has played a role as well. Al Qaeda lost its base in Afghanistan when the Taliban government that had provided it sanctuary was ousted from power. Osama bin Laden was finally found and killed by US special forces in Pakistan. Drones—unmanned aircraft that are remotely steered—have proven to be effective in killing a significant number of terrorists, including many of the most important leaders. Weak governments can be made stronger; governments that tolerate or support terrorism must be held accountable.

But progress is not to be confused with victory. Terrorists and terrorism cannot be eliminated any more than we can rid the world of disease. There will always be those who will resort to force against innocent men, women, and children in pursuit of political goals.

Indeed, terrorists are advancing in some areas. Pakistan remains a sanctuary for Al Qaeda and some of the world’s other most dangerous terrorists. A mixture of instability, government weakness, and ideology in countries such as Yemen, Libya, Somalia, and Nigeria is providing fertile territory for terrorists to organize, train, and mount operations—much as they did in Afghanistan a decade ago. New groups constantly emerge from the ruins of old ones.

There is also a growing danger of home-grown terrorism. We have seen it in Great Britain and the US. The Internet, one of the great inventions of the modern Western world, has shown itself to be a weapon that can be used to incite and train those who wish to cause harm to that world.

The question raised in October 2003 by the then US secretary of defence, Donald Rumsfeld, is no less relevant today: “Are we capturing, killing, or deterring and dissuading more terrorists every day than the madrassas and the radical clerics are recruiting, training, and deploying against us?" All things being equal, we probably are. But even small terrorist successes are costly in terms of lives, money, and making open societies less so.

What is to be done? Alas, there is no single or silver bullet. The establishment of a Palestinian state will not be enough for those terrorists who want to see the elimination of the Jewish state, any more than reaching a compromise over Kashmir will satisfy those Pakistan-based terrorists with bigger agendas vis-à-vis India. Reducing unemployment is desirable, of course, but many terrorists do not come from poverty. Helping to make societies in the Middle East and elsewhere more democratic might reduce the alienation that can lead to radicalism and worse, but this is easier said than done.

Of course, we want to continue to find ways to make ourselves less vulnerable and terrorists more so. But what may be most important, particularly in the Arab and Islamic communities, is to end any acceptance of terrorism. The Nigerian father who warned the US embassy in Lagos that he feared what his own son might do—before that same young man attempted to detonate a bomb aboard a flight to Detroit on Christmas Day 2009—is an example of just this.

Only when more parents, teachers, and community leaders behave likewise will recruitment of terrorists dry up and law enforcement authorities receive full cooperation from the populations they police. Terrorism must lose its legitimacy among those who have historically supported or tolerated it before it will lose its potency.

Haass is a former director of policy planning in the US state department and is now president of the Council on Foreign Relations.

Copyright: Project Syndicate, 2011.