Most counterterrorism policies fail, not because of tactical problems, but because of a fundamental misunderstanding of what motivates terrorists in the first place. If we're ever going to defeat terrorism, we need to understand what drives people to become terrorists in the first place.

Conventional wisdom holds that terrorism is inherently political, and that people become terrorists for political reasons. This is the "strategic" model of terrorism, and it's basically an economic model. It posits that people resort to terrorism when they believe -- rightly or wrongly -- that terrorism is worth it; that is, when they believe the political gains of terrorism minus the political costs are greater than if they engaged in some other, more peaceful form of protest. It's assumed, for example, that people join Hamas to achieve a Palestinian state; that people join the PKK to attain a Kurdish national homeland; and that people join al-Qaida to, among other things, get the United States out of the Persian Gulf.

If you believe this model, the way to fight terrorism is to change that equation, and that's what most experts advocate. Governments tend to minimize the political gains of terrorism through a no-concessions policy; the international community tends to recommend reducing the political grievances of terrorists via appeasement, in hopes of getting them to renounce violence. Both advocate policies to provide effective nonviolent alternatives, like free elections.

Historically, none of these solutions has worked with any regularity. Max Abrahms, a predoctoral fellow at Stanford University's Center for International Security and Cooperation, has studied dozens of terrorist groups from all over the world. He argues that the model is wrong. In a paper published this year in International Security that -- sadly -- doesn't have the title "Seven Habits of Highly Ineffective Terrorists," he discusses, well, seven habits of highly ineffective terrorists. These seven tendencies are seen in terrorist organizations all over the world, and they directly contradict the theory that terrorists are political maximizers:

Terrorists, he writes, (1) attack civilians, a policy that has a lousy track record of convincing those civilians to give the terrorists what they want; (2) treat terrorism as a first resort, not a last resort, failing to embrace nonviolent alternatives like elections; (3) don't compromise with their target country, even when those compromises are in their best interest politically; (4) have protean political platforms, which regularly, and sometimes radically, change; (5) often engage in anonymous attacks, which precludes the target countries making political concessions to them; (6) regularly attack other terrorist groups with the same political platform; and (7) resist disbanding, even when they consistently fail to achieve their political objectives or when their stated political objectives have been achieved.

Abrahms has an alternative model to explain all this: People turn to terrorism for social solidarity. He theorizes that people join terrorist organizations worldwide in order to be part of a community, much like the reason inner-city youths join gangs in the United States.

The evidence supports this. Individual terrorists often have no prior involvement with a group's political agenda, and often join multiple terrorist groups with incompatible platforms. Individuals who join terrorist groups are frequently not oppressed in any way, and often can't describe the political goals of their organizations. People who join terrorist groups most often have friends or relatives who are members of the group, and the great majority of terrorist are socially isolated: unmarried young men or widowed women who weren't working prior to joining. These things are true for members of terrorist groups as diverse as the IRA and al-Qaida.

For example, several of the 9/11 hijackers planned to fight in Chechnya, but they didn't have the right paperwork so they attacked America instead. The mujahedeen had no idea whom they would attack after the Soviets withdrew from Afghanistan, so they sat around until they came up with a new enemy: America. Pakistani terrorists regularly defect to another terrorist group with a totally different political platform. Many new al-Qaida members say, unconvincingly, that they decided to become a jihadist after reading an extreme, anti-American blog, or after converting to Islam, sometimes just a few weeks before. These people know little about politics or Islam, and they frankly don't even seem to care much about learning more. The blogs they turn to don't have a lot of substance in these areas, even though more informative blogs do exist.

All of this explains the seven habits. It's not that they're ineffective; it's that they have a different goal. They might not be effective politically, but they are effective socially: They all help preserve the group's existence and cohesion.

This kind of analysis isn't just theoretical; it has practical implications for counterterrorism. Not only can we now better understand who is likely to become a terrorist, we can engage in strategies specifically designed to weaken the social bonds within terrorist organizations. Driving a wedge between group members -- commuting prison sentences in exchange for actionable intelligence, planting more double agents within terrorist groups -- will go a long way to weakening the social bonds within those groups.

We also need to pay more attention to the socially marginalized than to the politically downtrodden, like unassimilated communities in Western countries. We need to support vibrant, benign communities and organizations as alternative ways for potential terrorists to get the social cohesion they need. And finally, we need to minimize collateral damage in our counterterrorism operations, as well as clamping down on bigotry and hate crimes, which just creates more dislocation and social isolation, and the inevitable calls for revenge.

This essay previously appeared on Wired.com.