The quest for answers to what possibly inspired Dzhokhar and Tamerlan Tsarnaev to plot two explosions near the finish line of the Boston Marathon exposes the complex and convoluted history of the North Caucasus, which for centuries has instigated violence across Russia.
The Boston bombings have shown how boiling inter-ethnic clashes in the Caucasus might have a global dimension.
The history of the Tsarnaev family closely mirrors Russia's sporadic policy toward its most ethnically diverse region, which suffers from near-daily violence.
The two brothers' father, Anzor, was born in the town of Tokmok, Kyrgyzstan, where his parents were deported during the 1944 forced resettlement program of Chechen and Ingush people to Central Asia.
Caucasus roots, Islam or a combination of both might have motivated the suspects.
"Operation Lentil," as the program masterminded by Soviet dictator Josef Stalin and secret police founder Lavrenty Beria was called, fostered the Chechen drive to gain independence from Moscow.
The two brothers' grandfather died in Kyrgyzstan when a shell exploded as he was scavenging for metal that could be sold as scrap, according to The Associated Press.
The brothers never lived in Chechnya, but their historic homeland's unyielding struggle for independence seemed to be one of the main reference points for their own quest for identity in the U.S.
Despite living in the state of Massachusetts for over a decade, the younger brother, Dzhokhar, set up an account on Vkontakte, Russia's largest social network, where he was subscribed to groups dedicated to Chechnya.
The Boston Globe reported that Dzhokhar also expressed an interest in the history of Chechnya by contacting a history professor at the University of Massachusetts Dartmouth who taught a course on the subject.
"Many Chechens are united by their national drama, by the two wars that have devastated their country. Even if they did not experience it directly, they can still be attached to it through their parents," said Gregory Shvedov, editor of the Caucasian Knot news agency, a leading source of information on the Caucasus.
"Young people whose families immigrated to another country can use their sense of belonging to their homeland to form friendships," he added.
As news reports broke about the brothers' Chechen origins, Chechen leader Ramzan Kadyrov wrote on his Instagram account that "any attempt to make a link between Chechnya and the Tsarnaevs, if they are guilty, is in vain."
"They grew up in the U.S., their views and beliefs were formed there," he said. "The roots of evil must be searched for in America."
Kadyrov came to power following two decades of incessant violence in the republic that he and his father, Akhmad Kadyrov, participated in insurgent fighting for independence. He and his father, who served as president before him but was killed in a bombing in 2004, defected to Moscow's side in 1999.
The Chechen insurgency against Russia was initially led by Dzhokhar Dudayev, the first president of the so-called Chechen Republic of Ichkeria, which proclaimed Chechnya's independence from Russia in 1991.
It might not be a coincidence that the younger Tsarnaev, who was born in 1993 in Kyrgyzstan at the time when Dudayev was at the peak of his power, was given the name Dzhokhar.
Dudayev, who was killed in 1996 by two Russian missiles that were guided to him through the interception of a conversation he was having on his satellite phone with a member of the State Duma in Moscow, became a cult figure for the Chechen rebellion.
The brothers' mother, Zubeidat, is an ethnic Avar, the predominant ethnic group in Dagestan, their father told The Wall Street Journal. Dagestan itself is inhabited by dozens of ethnicities and is home to mushrooming Salafist groups preaching the implementation of Sharia law in the republic.
Having an Avar for a mother makes the brothers only half Chechen, but the fact that Dzhokhar and Tamerlan are still being labeled as fully Chechen in the international media only highlights how difficult it can be to get through the ethnic complexity of the North Caucasus.
One of the most mysterious aspects of the lives of the two brothers is Tamerlan's trip to Dagestan for six months last year. During that time, he could have contacted Islamist insurgents who could have taught him how to make a bomb.
Andrei Soldatov, a prominent authority on security services, voiced doubt that the two brothers' activities were run from Russia because, among other factors, getting explosives in Makhachkala is very different from getting them in Boston.
Anzor Tsarnaev dismissed the notion that his elder son had links with the Islamist insurgency in Dagestan or Chechnya. Both sons showed an interest in extremist Islamic materials online.
At the same time, the North Caucasus insurgency has largely shifted from being driven by nationalist sentiments to being more Islam-oriented over the two decades. This transformation has manifested itself in the emergence of numerous Salafi radical preachers in the region, while one of the most respected moderate Sufi religious leaders, Sheikh Said Afandi, was slain last August.
Doku Umarov, the current leader of the Chechen insurgency, has changed his self-proclaimed title from being the underground president of the unrecognized Chechen Republic of Ichkeria to Emir of the Russian North Caucasus, declaring it an Islamic state of the Caucasus Emirate. A website affiliated with his group issued a statement over the weekend distancing the Chechen insurgency from the Boston bombings.
To what extent the Tsarnaev brothers might have been driven to radical Islamism by their interest in their homeland's intricate history has yet to be determined. But Shvedov, the Caucasian Knot editor, said, "You cannot claim that there is something special in the Chechen cultural code that drives them toward violence."