Chechnya, a tiny, mostly Muslim republic in the Caucasus Mountains of southern Russia, has a proud warrior tradition and a long history of resistance to Russian rule.
It took Russia decades to conquer Chechnya in the 19th century, and the Kremlin has never felt easy about its unwilling subjects. During World War II, Soviet dictator Josef Stalin deported the Chechens en masse to Central Asia.
Chechnya declared independence as the Soviet Union was collapsing in 1991. The war began three years later when President Boris Yeltsin sent in troops to reclaim the republic.
Moscow says the integrity of the Russian Federation is at stake. If oil-rich Chechnya is allowed to secede, other regions may follow, Kremlin officials say. Pride is also at stake: The once mighty Russian army is loathe to admit defeat at the hands of a few thousand lightly armed guerrillas.