Gessen describes the Tsarnaevs’ early immigrant days in a section aptly called “Dislocation,” with chapters titled “Love,” “Wandering” and “Dreaming of America.” These titles could easily decribe the early experiences of many immigrant families. The Tsarnaevs hoped for a better life here; they sought to escape the long, troubled history of the Chechen region, which has been riven by separatistism, Russian aggression and periods of war.

In America, the Tsarnaev family — mother, father, two sons, two daughters — struggled after arriving in 2001. Gessen takes us through this dark reality in a section titled “Becoming the Bombers,” in which she chronicles “a decade of broken dreams.” Here we see the financial and psychological pressures that force some immigrants to rely on the kindness of strangers, the charity of the state and the kinship of fellow immigrants. The family found a “miracle,” Gessen writes, in a Cambridge, Mass., former Peace Corps volunteer, Joanna Herlihy, who provided the family with an apartment, introductions and a lot of patience, as the Tsarnaevs broke promises and missed rental payments. At this time, younger brother Dzhokhar was “the sweet kid, the kid everyone loves,” the author writes.

Despite the assistance, the Tsarnaev family “witness[ed] the slow and catastrophic demise of a whole set of immigrant dreams,” Gessen writes. Things began to crumble as the brothers’ drug use picked up. “Pot was the scourge,” she explains. “Each member of the Tsarnaev family was descending into a separate personal hell,” Gessen writes. Media accounts have chronicled run-ins with police over alleged shoplifting, counterfeit money, marijuana possession and intent to distribute.

The family was experiencing a common trauma of the immigrant arc: grief over losing a former life. Years after leaving their homeland, Gessen writes, “it was as though the Tsarnaevs had never come to America.” Peering into their American home, one would see “the look every Chechen living room had.”

Drawing perhaps on her own experiences, Gessen is eloquent in describing the sense of loss an immigrant feels. “You never talk about the pain of dislocation,” she writes. “You do not describe the way color drains out of everyday life when nothing is familiar, how the texture of living seems to disappear. You breathe not a word of no longer knowing who you are, where you are going, with whom, and why — and the unique existential dread of that condition. Most important, you never question your decision: from the moment you cross the border, there is only ever the future.” The result is immigrants who fail to properly mourn the lives they’ve left behind.

As the daughter of Muslim immigrants from India, I understand that dynamic intimately. In 1992, when I was 26, I decided that I should marry within my culture and religion. So I left a Lutheran boyfriend from Iowa (who was a good match for me) for a Pakistani Muslim living in Washington (who was not). When I mentioned this to my boss, he gently pointed out that ill-advised actions often result from an inability to grapple with the past. In my case, I married the Pakistani Muslim, and my union lasted just a little longer than the first bethrothal of Kim Kardashian. Clearly, like many immigrants, I was struggling with how to shape my newly emerging identity.

Tamerlan Tsarnaev, the older brother, and his mother, Zubeidat, may have been facing the same struggles in 2009 when they began to study the Koran, getting their lessons from “the Internet and . . . occasional intense conversations with better-informed acquaintances.” The book provides little insight into the brothers’ Muslim teachings as young children, except to say that they were not schooled in extremist thought. At this later time, however, Zubeidat started wearing a hijab, and Tamerlan showed increased devotion to his religious life. He threw away binders he’d put together when he was younger that contained clippings on how to seduce women and hypnotize people.

The book has a splendid opportunity to reflect on the community’s role, particularly that of the Muslim community, in guiding young people toward positive, healthy lives. It is important to hold individuals, families and communities accountable for the development of young newcomers to America. But Gessen misses her chance to explore this crucial piece of the immigrant puzzle. Neuroscientists, psychiatrists and psychologists increasingly analyze the immigrant experience in the context of trauma. Immigrants experience not only a geographical upheaval but a severe blow to their identity. The Tsarnaev story reminds me, as a mother of a 12-year-old next-generation immigrant boy, that it is vital to promote a psychology of integration, adaptation and healing.

In place of a deep analysis about overcoming the challenges of assimilation, Gessen chooses to engage in a narrative of Muslim immigrant victimhood. She lays much of the blame for the Tsarnaevs’ actions on alleged harassment by the FBI. Whether or not the Tsarnaevs were influenced by extremists, she rejects notions that some Muslims become radicalized by jihadists, arguing that the United States and its reactions have “probably done as much” as al-Qaeda to create a “worldwide community of jihadists.”

She even asks, “Is it conceivable that the Tsarnaev brothers were not the marathon bombers?” — and answers: “Yes, it is conceivable.” Gessen contends that the FBI hatches terrorist plots as sting operations to nab possible terrorists but sometimes reels in law-abiding citizens. From Sept. 11, 2001 to 2013, Gessen writes, “the number of terrorist attacks carried out on American soil by people connected to Islamic organizations numbered zero, but trumped-up terrorist plots numbered in the dozens, and the people who went to jail because of them in the hundreds.” Gessen proposes bizarre theories for which she doesn’t provide evidence, such as one about Tamerlan possibly having been a FBI informant who went rogue.

She notes that the mother-in-law of a friend of Tamerlan’s had an FBI agent’s number saved on her phone under the name “Terrorist.” That friend, Ibragim Todashev, was killed by an FBI agent in a scuffle during his questioning about possible involvement in a triple murder. To me, many Muslim organizations stoke distrust of the FBI and law enforcement by concocting conspiracy theories built on narratives of “bad cops.”

As we saw at his trial, the younger brother, Dzhokhar, didn’t assert his innocence in the marathon bombing. Before his capture, he wrote a note found bloody and bullet-ridden in a boat where he hid after the attack. “We Muslims are one body, you hurt one you hurt us all,” the note read. “I don’t like killing innocent people it is forbidden in Islam but due to said [illegible] it is allowed.” A bullet hole was responsible for the illegible word.

As the Tsarnaev story shows, immigrants suffer the emotional challenges of dislocation, hardship and trauma, and sadly, these vulnerable brothers turned their struggles into terror for which there is no excuse.

bookworld@washpost.com