When American troops found themselves fighting Iraqi terrorists in towns and cities, pundits predicted that Americans would suffer the same dismal fate of the Russian army, which got beat up real bad by Chechen irregulars in the 1994-6. But there was no replay of the Russian disaster in Iraq. The Americans proved very effective at street fighting. And one of the reasons was the U.S. Marine Corps project to interview Chechens who had fought the Russians in the early 1990s. The marines conducted their interviews in 1998, and modified their urban combat tactics to deal with the Chechen methods that had tripped up the Russians so badly. The U.S. Army also got in on this, with the result that, even though the Iraqis tried to use some of the Chechen tactics, they quickly found out that the Americans were not reacting like the Russians.
In 1994, the major problem the Russians had was not the clever tactics of the Chechens, but that the Russian troops were poorly trained and led. That was not the case with U.S. forces in Iraq or Afghanistan. But the Chechen tactics were well thought out, and implemented skillfully, and to great effect. The Chechens were more efficient, and led, than most Iraqis U.S. forces encountered. In fact, Chechens have served as mercenaries for Middle Eastern leaders for centuries. American troops have encountered Chechen fighters in Iraq and Afghanistan, and killed them.