Can anything more be done to stop jobless, hopeless, rootless, and alienated young Muslim men, in the Islamic world and in the West, from embracing violent Islamism? Curbing the flow of recruits will not, of course, eradicate groups like the one calling itself the "Islamic State.” Nor will it ensure the prevention of atrocities such as November’s Friday the 13th massacres in Paris. But any long-term solution requires curtailing the ability of extremists to attract newcomers.

For the foreseeable future, hard measures will continue to be necessary: tough policing, intrusive intelligence gathering, effective border protection, and oppressive airport security. And sometimes, as well, outright military attack will be called for – particularly where the innocent are at immediate risk (as with the Yazidis in Iraq) and the targets are clear.

But violent jihadism is a complex problem that requires a similarly complex response. Because military force alone will always risk creating more new fighters than it kills, it is not softheaded to insist that we pay attention to the underlying causes of Islamist extremism, not just its surface manifestations.

In part, that means addressing the political grievances of the Arab and Islamic world, not least Israel’s continuing occupation of Palestinian land. This is not to appease the violent extremists, many of whom will not be moved in the slightest by such initiatives. The point is to change the atmosphere in the communities in which extremism ignites, denying it some of the oxygen it needs to spread.

Reducing the pool of hopeless young men also requires implementing strategies to expand economic opportunity, both in the developing world and in the most depressed pockets of the developed world.

It also needs to be recognized that fighting extremism is a matter of opening more human rights and democracy channels for the expression of demands and grievances, as the International Crisis Group (ICG) has long argued for Central Asia and North Africa. When the only open door is that of the mosque, it is not surprising that popular discontent often takes on an Islamist cast.

But these longer-term strategies are all difficult to implement. We need to support them with preventive strategies that have an immediate payoff. When an epidemic is raging, the most pressing task is to interrupt the transmission of the disease, change the behavior of those at highest risk, and get community support for that change.

Since 9/11, community-based "Countering Violent Extremism” programs have aroused interest in Europe, the United States, and in countries like my own. They aim, in various ways, to identify the early warning signs of Islamist radicalization and likely recruitment. Among the best known are the British government’s "Prevent” program, and a pilot project by the US government in Boston, Los Angeles, and Minnesota. Perhaps the most effective initiative so far in turning back young men from traveling to Syria or Iraq is Germany’sHayat program, which works with relatives, friends, teachers, and employers in mentoring those deemed vulnerable to the appeal of violent extremism.

What is already clear is that the most successful programs are those that are least visibly associated with government and law-enforcement authorities; those developed in close consultation with local communities; and, above all, those that are most practical and specific, relying primarily on individual interventions.

Those young men (and occasionally women) who are susceptible to extremism’s appeal respond best to those they trust – people who can help them step back from violence in a way that does not cause them to lose face. Sidney Jones, in her brilliant work for the ICG on Jemaah Islamiyah in Indonesia, found that potential recruits were not at all receptive to exhortations from moderate Muslim leaders to eschew violence; they could, however, be turned away by those whom they saw as having legitimacy within the jihadist movement.

Not every policymaker, government program, or non-governmental organization working on violence prevention gets this core message. But some do, not least Cure Violence, founded by the former World Health Organization epidemiologist Gary Slutkin. His organization works on the principle that deadly violence is a contagious disease, capable of being halted by appropriate intervention. It has done wonderful work over the last 15 years, directly and through partner organizations, in reducing – by up to 70% – the incidence of shootings and homicides in some 60 communities in 25 cities in the US, Latin America, Africa, and Iraq.

Just a day after the terrible bloodshed in Paris, I met in a storefront on Chicago’s South Side with the organization’s local "CeaseFire” group, a half-dozen battle-scarred veterans of that city’s mean streets. They then dispersed – as outreach workers or "violence interrupters” – for a long Saturday night of taking the temperature of potential hot spots, talking down those who needed calming, and identifying those who needed more sustained help with the issues that were taking them to the edge. They knew their local community intimately, were totally accepted and trusted as non-threatening peers – and had a terrific track record of preventing shooting and killing.

Cure Violence is only just beginning to apply its experience to countering violent extremism, but it is keen to do so on the ground in both the Middle East and the West. There is every reason to believe that the peer-group persuasion strategies it has honed in some of the world’s toughest urban environments will work at least as well with potential jihadists.

Gareth Evans, former Foreign Minister of Australia (1988-1996) and President of the International Crisis Group (2000-2009), is currently Chancellor of the Australian National University

Copyright: Project Syndicate.