The ethnic roots in Chechnya of Boston Marathon bombing suspects Tamerlan and Dzhokhar Tsarnaev is feeding theories by terrorism experts that an Islamic insurgency in the rebellious, war-torn region of Russia played a part in their radicalization.
The collapse of the Soviet Union in the early 1990s triggered a Chechen independence movement that led to two periods of intense warfare from 1994 to about 2006 and smaller-scale violence since then that has taken tens of thousands of Russian and Chechen lives. The Chechen capital of Grozny was largely turned into a moonscape through bombing as the rebels were subdued.
Terrorists from Chechnya and neighboring provinces carried out a long series of attacks in Russia, including a 2002 raid of a Moscow theater in which 129 hostages died; a 2004 hostage-taking at a school in the southern city of Beslan that killed more than 330 people, and numerous bombings in Moscow and other cities.
But though Russians were the usual targets, Chechen terrorists have been arrested in recent years in Denmark, Belgium, France and Spain on charges of plotting attacks.
Brian Glyn Williams, a professor at the University of Massachusetts in Dartmouth and an expert on the Chechen region, said the notion of anti-Americanism among Chechen nationalists would be surprising. One of the main heroes of the Chechen people is George Washington, Williams said.
Mitch Silber, former director of intelligence analysis for the New York Police Department, suspected Chechen nationalism was the seed of a violent, radical change for the Tsarnaev brothers, evolving into a broader, jihadist-inspired enmity for the United States.
"Somewhere along trajectory, the anti-Russian sentiment twisted to a pro-jihadist, anti-Western sentiment," said Silber, who has studied radicalization of other young Islamic men living in the West.
"That is not in doubt for me," said Silber, an executive managing director at K2 Intelligence, a private consulting firm. "The question is what was the path ."
It is unclear whether operational links have developed between international jihadist groups and Chechen rebels.
Some Western analysts note that overseas Islamic fighters traveled to Chechnya to help fight Russians.
But a New York law enforcement intelligence expert who didn't want to be named said there have only been two documented cases of Chechens joining jihadists abroad: in 2012 in Syria and 2009 in Pakistan.
With The Associated Press