As the U.S. tries to process the news that the two suspects in the Boston Marathon bombing had ties to the Russian republic of Chechnya, Russians and Chechens know what it means for them: trouble.

Little is known in Russia about the brothers, Tamerlan Tsarnaev and Dzhokar Tsarnaev. Apparently, the family moved to the U.S. more than a decade ago to seek refuge from Chechnya, which had a long and brutal secessionist conflict with Russia. Relations between ethnic Russians and Chechens remain fraught, and Chechen nationalists and religious fanatics have carried out numerous terrorist attacks on Russian soil.

The initial Russian reactions were incredulous: What do Chechens want with Boston? “Russian Chechens from Kazakhstan commit an act of terror in Boston for some unknown reason,” journalist Tikhon Dzyadko wrote on Twitter. “Hello globalization.”

Whatever the brothers’ motivations, Russians worried that the young men’s origin would have a bad effect on American attitudes toward Russians in general, and specifically toward refugees from Chechnya.

“This will definitely affect relations” between Russians and Americans, security expert and former parliament deputy Gennady Gudkov told the Metro newspaper. “Americans will have a worse attitude toward Chechens, Dagestanis and all people from the Caucasus. This is inevitable.”

As Twitter user @nice_anastasia put it: “Now the consul will be even stricter when issuing visas.”

Ramzan Kadyrov, the strongman Russian President Vladimir Putin installed to restore calm in Chechnya, reacted to the news with irritation. “We are accustomed to everything that goes wrong in the world being associated with Chechens,” he said, according to government-owned RIA Novosti news agency. “But accusations are not proof yet that these people were involved. In any case, they were brought up in America. This is their education.”

Russians are finding it hard to understand why two Chechen brothers, who have lived in the U.S. for years, would have attacked a country that had done them no wrong.

A sparse account attributed to Dzhokar on VKontakte, a Russian-language social network, suggested more animosity toward Russia than toward the U.S. One post contained a bitter joke referring to the treatment of people from the Caucasus region in Russia: “A Dagestani, a Chechen and an Ingush are riding in a car. Question: Who is driving? Answer: A cop.”

Elder brother Tamerlan, too, made comments showing antipathy for Russia. In captions on a photo gallery of him training for a boxing match, he was quoted as saying that “until his native Chechnya becomes independent, Tamerlan would rather compete for the United States than for Russia.”

Russian nationalists saw the news from Boston as a vindication of their belief that Chechnya is a terrorist region and Moscow was right to suppress it. American “supporters of Chechen independence have been blown up by those independence fighters,” programmer Alexei Shurygin wrote on Vkontakte.

This being Russia, there was no shortage of conspiracy theories. Some suggested a link between the attack and the recent U.S. decision to include Kadyrov in a list of undesirables who would be denied entry to the country. “Right after what happened I said aloud: Maybe America should not have put the leader of Chechnya on any public lists,” TV producer Vera Krichevskaya wrote on Facebook.

A man calling himself Anzor and claiming to be the brothers’ father offered his own version in an interview to the Interfax news agency. “In my opinion, my children were set up by the special services because they were Muslim believers. Why was Tamerlan killed? They were supposed to take him alive. The younger son is on the run now,” he said. “We expected him for holidays. Now I don’t know what will happen.”

Alexei Filatov, head of the veterans’ association for Russia’s elite Alfa anti-terrorist unit, told the daily Kommersant that the true organizers of the attack must have been Americans unhappy with President Barack Obama’s “intention to cease active anti-terrorist activities.”

“These are people hired to perform the terrorist attack,” he said. “Judging by the way it was executed, the people who ordered it would hate for their identity to become public. If it were some radical organization, Islamic or otherwise, it would have claimed responsibility.”

(Leonid Bershidsky, an editor and novelist, is Moscow correspondent for World View. Opinions expressed are his own.)

To contact the writer of this article: bershidsky@gmail.com.

To contact the editor responsible for this article: Mark Whitehouse at mwhitehouse1@bloomberg.net.