When Chechen fighters were known to be dug into a valley along the mountainous border with Pakistan at the outset of a U.S. "clear and hold" mission, "I was ready to get hammered on. I've never seen a foreign fighter walk so alone and not give a damn," the soldier added.
That reputation, however, may have led many in the U.S. military and intelligence to inflate the Chechens' true numbers on a battlefield that is often as foggy as the actual border itself is undefined.
University of Massachusetts at Dartmouth scholar Brian Glyn Williams, who has searched for evidence of Chechen foreign fighters on the ground in Afghanistan while under contract with the U.S. military and CIA, said it wouldn't be surprising if some had joined the Taliban but he insists such tales are mostly a "Chechen jihadi myth."
"I think the lack of evidence is telling. There is a total absence of any names or anything tangible," Williams told ABC News this week.
Christopher Swift, a Georgetown University scholar and ABC News consultant who has done research in Afghanistan and interviewed scores of militants in the North Caucasus, agreed there is little hard proof that as many Chechens fought in Afghanistan as has been implied by military reports and noted that none were ever held at the U.S. terrorist prison at Guantanamo Bay, Cuba.
But, Swift added, "That's consistent with fighting to the death. These fighters are not going to get captured."
Some Chechens were reputed to have fought with al Qaeda Arabs against U.S. troops during Operation Anaconda in 2002 -- but it may have been the birthplace of the myth.
"It was a pervasive rumor at the time. But I never saw a Chechen. In fact, I'm not sure anyone did," Brandon Friedman, a 101st Airborne platoon commander in Anaconda, told ABC News. Friedman later wrote "The War I Always Wanted" about his experiences.
Williams and Swift said al Qaeda militants who spoke Russian -- often a unifying language for foreign fighters from the former Soviet Union -- and whose corpses appeared Caucasian were presumed to be Chechens, even if they were actually Uzbeks, Tajiks or from other ethnic groups.
"I didn't run into any Uzbeks but I distinctly recall several Chechens with the Islamic Movement of Uzbekistan," said the active-duty senior Special Operations officer, recalling combat operations in 2001-2002.
An experienced former operator from America's "tier one" black Special Operations group, "Delta Force," confirmed that misidentifications were common over the course of the war but said some foreign fighters were indeed Chechens. They entered combat as extremely disciplined and well-equipped teams with good weapons discipline and expensive personal gear made by The North Face.
"There were fighters that came to train, came to fight to support the jihad, and those that came to fight and learn U.S. tactics to take back to Chechnya to fight the current Russian government," said the veteran operator, whose affiliation with "The Unit" remains classified.
Any Chechens who survived their confrontations with Navy SEAL, Army Green Beret or Delta operators working for CIA or the Joint Special Operations Command, will not likely forget -- or forgive -- their American adversaries.
"It's safe to say that anyone from the Caucasus who's left the region and 'gone global' would likely see the United States -- and U.S. civilians -- as legitimate targets," said Georgetown's Swift. "This would be particularly true for those who may have fought against U.S. Forces anywhere, including Afghanistan."