Finding and stopping terrorists before they strike is often compared to looking for a needle in a haystack, a cliché that speaks to the difficulty of preventing a crime that, while deadly, is uncommon. Counterterrorism officials still suggest that the task would become easier if they could use profiling to target Muslim communities. In other words, if they could shrink the size of the haystack.

But a new book by Dr. Marc Sageman, a veteran counterterrorism researcher and former CIA operations officer, argues that this approach, even if carried to its fullest extension in a nightmare scenario for civil liberties, would still be ineffective, because jihadist terrorism is such a statistically rare phenomenon.

In his book “Misunderstanding Terrorism,” Sageman counts 66 Islamic jihadist terrorist plots in Western countries between 2002 and 2012, involving a total of 220 perpetrators. This figure works out to an average of 22 terrorists per year, across a population of roughly 700 million people. Even narrowed to just the Muslim population in Western countries, estimated at roughly 25 million people, that’s less than one in 1 million Muslims a year who could be considered terrorists.

Describing a hypothetical dragnet conducted by Western countries that correctly identified terrorists 99 percent of the time, but accused innocent people 1 percent of the time, Sageman asks us to imagine the following:

If all the various police departments operating in the West collaborate and carry out a gigantic sweep by applying this profile to their respective Muslim populations in order to catch terrorists hiding in their respective societies, they would arrest all 22 terrorists that emerge in a given year. However, they would make a mistake 1 percent of the time for 25 million people, which comes to 250,000 people. Therefore, in order to catch all 22 global neo-jihadi terrorists, they would put 250,000 Muslims in jail by mistake.

Because terrorism is so uncommon, he writes, any strategy for combating it that involves policing entire communities is likely to end up harming huge numbers of innocent people — thus feeding the same climate of alienation and hostility that fosters political violence in the first place.

In the 1980s, Sageman helped organize Afghan resistance fighters against the Soviet Union. Over the decades since, he has interviewed hundreds of individuals accused of involvement in jihadist terrorism, documenting the circumstances of their cases and their personal motivations.

“Misunderstanding Terrorism” by Marc Sageman

“Misunderstanding Terrorism” analyzes every jihadist terrorist plot that occurred in the United States and Europe over a 10-year period ending in 2012. The study excludes nonviolent terror-related cases, such as those involving financial donations or other material support charges, as well as sting operations in which plots were developed by agent provocateurs — a tactic favored by U.S. law enforcement agencies but viewed with skepticism in many European countries. His research comes to two broad conclusions. The first is that violent terrorist plots in Western countries are a statistically tiny phenomenon, which makes blanket counterterrorism approaches an ill-suited response. The second takeaway is that “social identity theory” — that is, how people self-identify in a crisis — is the primary motivating factor behind terrorist attacks.

Despite efforts to protect civil liberties, Sageman writes that profiling-based approaches have led the United States to “grossly overestimate the violent terrorist threat and commit a very large number of assessment errors.” The politically driven manipulation of the threat of terrorism has led Americans to “fibrillate in fear and bankrupt [themselves] with security” in response to a threat that is much smaller than they have been led to believe.

But why does the threat of terrorism resonate so much more in the popular imagination than other dangers? Sageman argues that identity politics influence our response to violence, both for victims and for perpetrators. Most Americans perceive terrorism as something that comes from an “out-group” rather than from people with whom they identify. As a result, an attack creates a sense of solidarity, leading people to react emotively, in contrast to the oft-muted response to more common forms of violence. This identity-driven reaction to terrorist violence also causes people to overestimate how prevalent terrorism really is, making them willing to commit wildly disproportionate resources to fighting it.

Sixteen years after 9/11, the war on terror still appears to have no end in sight, driven on by a circular logic of violence and retribution. Under the Obama administration, the U.S. government tried to frame its counterterrorism programs as not specifically targeting Muslims, while still carrying out airstrikes overseas and launching controversial “countering violent extremism” programs in Muslim communities. Although in recent years some national security experts like Sageman have begun to point out the self-defeating nature of American counterterrorism policies, Donald Trump’s approach – focusing explicitly on Muslim communities, implementing discriminatory immigration policies, expanding military action abroad, and declaring an open-ended war against the amorphous concept of “radical Islam” – isn’t a course correction.

Sageman argues that identity politics are also what fundamentally drives the terrorists themselves. U.S. government policies can consciously or inadvertently fuel a sense of conflict between different groups, in this case Muslims and Westerners. (Several government studies have also pointed to politics as a driver of terrorism, finding U.S. foreign policy as the most frequently cited motivation.)

“All of us see the world through the prism of identity, so when we see an escalation of a conflict happening between ‘us’ and ‘them,’ it inevitably leads some people toward political violence,” Sageman told The Intercept in an interview. “Looking at it in terms of foreign policy, when the government attacks other countries, oftentimes people who have a link to that country or identify with the people there will start categorizing themselves alongside the victims of those attacks.”

By categorizing huge swaths of the global population as enemies or potential enemies, Trump is engaging in hostile posturing toward very large numbers of people who pose no threat to the United States. Meanwhile, the rising death toll from his military actions has the potential to be a force-multiplier for terrorist recruitment. Thanks to advances in information technology, the destructive effects of U.S. military actions are more easily recorded and disseminated than they were a few decades ago. As they escalate, these actions are likely to trigger an emotive “in-group” reaction among those people who perceive themselves as targeted, Sageman says. Likewise, terrorist attacks in Western countries will trigger an emotive “in-group” reaction among Americans, continuing the cycle.

In Sageman’s view, factors like ideological extremism and economic deprivation, sometimes cited as root causes of terrorist violence, are secondary to political identity.

He notes that the phenomenon of identity-based violence has been repeated in different cultural and religious contexts in American history – including by people most Americans would now consider part of the “in-group.” During the Mexican-American War of 1846, an entire battalion of Irish Catholics fighting in the U.S. Army defected to the Mexican side out of a sense of solidarity with the suffering of their Mexican co-religionists, and in protest of the discrimination then faced by Catholics in the United States. Although this episode is largely forgotten today in the U.S., its memory continues to linger for some in Mexico and Ireland.

Sageman believes that the only path to winding down our present conflict is to expand our own “in-group.” In the United States, Sageman said that would mean “bringing everybody into the fold and saying that we’re all Americans, equally, and not just focusing exclusively on one group and defining them as suspicious and not completely part of the fold.”

“Crafting a sense of national identity that includes people instead of driving them further apart is what a leader is supposed to do,” he added. “If we are unable to respond to real threats in a proportional and focused manner, and if we see continue to see this cumulative radicalization of discourse, we will end up with more political violence at home, not less.”

Top photo: Law enforcement officers secure the area where they allegedly arrested terror suspect Ahmad Khan Rahami following a shootout in Linden, New Jersey, on Sept. 19, 2016.