First off—who are these young men?
From what I’ve been able to gather about the Tsarnaev brothers, only one direct link to Chechnya has emerged. Anzor Tsarnaev, their father—who claims to have spoken with one of his sons the day after the Marathon attacks—lives in Makhachkala, Dagestan, a small region of the Russian Federation that borders Chechnya on the Black Sea. The father has said that his elder son, Tamerlan, now dead, visited “relatives” in Chechnya last year. (U.S. officials report that Tamerlan flew to Moscow in January, 2012, and returned to the U.S. six months later.)
The young men’s father is said to be an ethnic Chechen, but born and raised in Kyrgyzstan—a former Soviet republic in Central Asia. (On Red Army Day in the winter of 1944, Stalin deported hundreds of thousands Chechens from their homeland—many died, but many who survived the journey resettled in Central Asia.) The Tsarnaevs' mother, who does not have a traditional Chechen first name, is said to be from Dagestan. Tamerlan, the older brother, was reportedly born in Dagestan, while his younger brother, Dzhokhar, was born in 1993—in Kyrgyzstan. So it would seem—at this early point—that their ties to Chechnya were tenuous. It remains to be seen, if in fact Tamerlan Tsarnaev visited Chechnya last year, what he did during his time there.
How big is the Chechen community in this country?
Extremely small. There’s no official organization, no association, or even an online community, of ethnic Chechens living in the US. It cannot even be termed a “Diaspora”—I’d estimate the total at no more than 250 people. One Chechen refugee in New York tries to keep track of every Chechen in the country the refugee has met—the list runs to 81 people. They’re spread out across the country—New York, Miami, Washington, D.C., New Jersey, California, and Boston.
European nations have taken far greater numbers of refugees from Chechnya. In Austria, the Czech Republic, France, Belgium, and Germany, for instance, the number of formerly Chechen nationals ranges in the thousands, if not tens of thousands. Turkey, a country close to Chechnya, and with traditional and ethnic ties, may have the largest population: with an estimated 50,000 ethnic Chechens.
Why have they left their homeland?
War. Chechnya—a tiny region in the Caucasus that’s about the size of Connecticut—has suffered two wars in recent years. From 1994-96, in the “first” war, a charismatic (if unhinged) former Soviet air force general named Dzhokhar Dudaev sought to free his people from the Kremlin’s control and create a would-be statelet. Then in the fall of 1999, the “second” Chechen war began—dubbed Putin’s War, after the newcomer in the Kremlin, then all but unknown in the West: Vladimir Putin. Though the true death toll will never be known, human rights experts estimate the total dead—of Russians and ethnic Chechens—in the hundreds of thousands.
But one point bears remembering: if in the first war, the Chechen rebels were “freedom fighters” in the old Ronald Reagan/Margaret Thatcher way of seeing things, young men hungering for independence in a guerrilla war of decolonization, Putin’s War marked a sharp turn. Beginning in the fall of 1999, the Russian assault was far more brutal (more troops, even more bombs), and the Chechen response further radicalized. The talk soon turned from sovereignty to revenge, and among the young, and most militant, fighters, those with the least experience of the Soviet yoke, the rebellion carried a new name: jihad.

Ruslan Tsarni, a man claiming to be an uncle of the Tsarnaev brothers, has said that they received “asylum” in 2003. How common is that?
Very rare. First, it is unclear if the uncle meant “political asylum,” or if he knows the legal status of their residency in this country. But if that claim proves true, it would seem an exception. Only a few ethnic Chechens—the precise number is not known—are here because they have succeeded in winning political asylum. Ilyas Ahkmadov, the former Foreign Minister (1999-2005), who fought during the first Chechen-Russian war, lives in the U.S. But even with the backing of some of Washington’s most prominent politicians, Akhmadov has had to wage a long and arduous campaign to stay.
Some of the “Chechens” in this country are even second—and third-generation Americans—families whose roots lie in Jordan, among the Chechen Diaspora there, which formed largely after Stalin’s mass deportation of the Chechens.
In the aftermath of "Putin's War", with Moscow again firmly in control in Chechnya, have Chechen fighters turned increasingly to terrorism?
Again let's be clear: It remains to be established that the Tsarnaev brothers had any strong link to Chechnya—either its recent history of warfare, or to the terrorists, both native and foreign, who have sought to wage jihad in the name of Chechen independence.
The brothers, though, had fled a region long wracked by violence. Whether in Makhachkala or Boston, they were likely to have known its toll.
Since 2000, Russians and Chechens have seen a succession of deadly terrorist attacks arising from the wars in the Caucasus. In June 2000, Khava Barayeva, a relative of two Chechen field commanders, blew herself up in a truck bomb at a military checkpoint in Chechnya—becoming the world's first known Chechen female suicide bomber. In May 2002, a bomb at Victory Day parade in Dagestan (where the Tsarnaevs' parents are reported to live now) killed 35 people, including 12 children. That fall came the Moscow theater siege—when 41 terrorists, including 18 women, seized a Moscow theater, holding almost 800 people hostage for three days. In the end, Russian Special Forces stormed the theater, killing all the terrorists and 130 hostages. (The hostages were killed by the gas the Russians deployed.)
The string of attacks that has followed is seemingly without end. But none looms larger in Russians’ memory than the siege in Beslan. On September 1, 2004, the first day of school, a group of terrorists—among them Chechens, Ingush (a neighboring ethnic group of the North Caucasus) and at least one ethnic Slav—took nearly 1,200 civilians hostage in a middle school in Beslan, North Ossetia—a region in Russia to the west of Chechnya. By the siege’s end, an estimated 1,000 civilians were killed or wounded—hundreds of them children. Putin leveled the blame at the "intervention of international terrorists." But Aslan Maskhadov, the former rebel leader, and once a sober-minded negotiator with the Kremlin, spoke out from hiding to denounce the attack. The Beslan operation, Maskhadov said, was the work of "madmen" driven by revenge, not insurgents fighting for freedom for their homeland.
In the years since Beslan, few Russians speak of "Chechen rebels" any more, but rather of "Chechen terrorists." And the long-suffering Chechens who remain in their homeland have seen it return to the Russian fold. Its capital, Grozny, once leveled to ruins that resembled Stalingrad in World War II, is now rebuilt, with gleaming banks and towering apartment buildings. But Chechnya has become a republic of fear, the fiefdom of one man: its mercurial 36-year-old president, Ramzan Kadyrov.