If anything is to be learned at this point, just days after the bombings at the Boston Marathon, it is that every terrorist attack should be approached as a discrete event, disaggregated from assumptions about groups, "hallmarks" and ethnicity. Just ask the young Saudi man injured by the explosion, whom some in the news media wrongly tagged as a suspect. We should take a careful, measured look at the inevitable talk of the suspected bombers' links to Chechnya.

The Tsarnaev brothers, Tamerlan, 26, and Dzhokar, 19, would have been babies in 1994 when their ethnic homeland, a Russian republic in North Caucasus region, was ripped apart by a war of independence. I was editing a newspaper in Russia at the time and visited Chechnya just before the war to talk to the republic's new president, a former Soviet air force general by the name of Dzhokar Dudayev. Dudayev was a strange character but not remotely Islamist. He liked to drink and fought with the Soviet military against the mujahedeen in Afghanistan. Chechens are Muslims, but of the moderate Sufi rite. Islamic jihad played no role in their bid for independence.

For the Chechen nationalist cause, a terrorist attack in the U.S. carried out by Chechens is an unmitigated disaster. Russian President Vladimir Putin has sought for years to portray the Chechen conflict as purely a problem of jihadi terrorism, directly equivalent to al-Qaeda. He has urged the U.S. and Europe to join him in fighting this scourge shoulder-to-shoulder, rather than quibble over human-rights abuses committed by Russian forces in Chechnya.

Putin never quite succeeded in selling his simple Chechnya-as-counterterrorist-problem narrative. The U.K., for example, has refused to extradite Akhmed Zakayev, an important Chechen leader and negotiator. In bombing the U.S., Chechens would only succeed in making the U.S. more receptive to Russia's anti-Chechen arguments.

Putin is right, though, about a worrying slice of young Chechen men, who have become radicalized. They are jihadis first, rather than nationalists, even if those lines are very much blurred.

Over time, jihadis from throughout the Muslim world made the Chechen conflict their own. They began arriving in 1995 with the Jordanian-born Saudi Umar Ibn-Khattab, who fought in Afghanistan and had known Osama bin Laden there. In 1997, the current al-Qaeda chief, Ayman al-Zawahiri was caught in the neighboring Russian republic of Dagestan, as he tried to get to Chechnya.

Chechen jihadis have carried out horrific terrorist attacks in Russia, including the seizure of hostages in a Moscow theater in 2002, which resulted in 130 civilian deaths, and the 2004 attack on a school in Beslan, close to Chechnya, in which at least 330 people died, half of them children.

Chechen Islamists can now be found on the front lines in Afghanistan, Somalia and Syria. In 2010, a Chechen boxer who lived in Belgium was caught trying to bomb the Danish newspaper that published cartoons depicting the prophet Muhammad, which had triggered protests around the Muslim world. These Chechens are part of the global jihad.

It's impossible to say where Dzhokar and Tamerlan Tsarnaev fit into this Chechen story. As Lorenzo Vidino, a senior researcher at Zurich's Center for Security Studies, who has studied Chechen Islamists, put it: "It could be these guys are homegrown, and their being Chechen is just a footnote."

The Tsarnaevs appear to have lived their early years in Kyrgyzstan, where there are substantial Chechen diasporas because of Stalin's mass deportation of the Chechen population as alleged Nazi collaborators in 1944. The family moved to Dagestan for a year in 2001, where the Associated Press today interviewed a man saying he was the brothers' father.

From there the Tsarnaevs emigrated to the U.S., when Dzhokar Tsarnaev, still on the run, would have been a young boy. His father described Dzhokar to the Associated Press today as "an angel." He clearly wasn't that, but we should be slow to draw conclusions as to exactly what may have persuaded him to become a terrorist.

(Marc Champion is a member of Bloomberg View's editorial board. Follow him on Twitter.)