The fighting in Dagestan raises fears that one of the world's most ethnically-complicated and unstable regions has the potential to explode into uncontrollable turmoil.
Statements from the Chechen government that Russian bombing of its territory amounts to a declaration of war has heightened tension even further.
The Caucasus area has such an intricate patchwork of nationalities that it makes the Balkans look simple. In Dagestan alone there are up to 40 different peoples and in mountainous areas there is a different people and a different language in every valley.
The region came under Russian control in Tsarist times, and it was the Chechens who held out longest in the wars against rule from St Petersburg.
Today, it is again the Chechens who are proving the most difficult to control from Moscow. But Chechnya's effective independence, following the brutal 20-month war in 1995 and 1996, managed to keep the situation from boiling over.
All that changed on August 7th when forces led by the Chechen warlord, Mr Shamil Basayev, and a Jordanian militant known only as Khattab moved into Dagestan.
Rebels, many of them followers of the ultra-strict Saudi Arabian Wahabi sect of Islam, proclaimed a holy war against what they described as the Russian Kaffirs (unbelievers) and set up a provisional Islamic government for Dagestan.
Most Dagestanis, who practice a more liberal form of Islam, do not support the rebels, and large sections of the Russian federal forces in the current conflict are made up of local Muslims.
Even in Chechnya, the Wahabi rebels have not been fully supported. In the elections which followed the Chechen war, the moderate Gen Aslan Maskhadov roundly defeated Mr Basayev, yet still has the support of most Chechens.
But Gen Maskhadov's military prowess in leading the Chechens to victory over Russian forces has not been matched by an ability to control the post-war situation. Large sections of Chechen territory are now run by warlords such as Mr Basayev, and the kidnapping of westerners has become a lucrative source of revenue.
Russia's bombing of villages inside Chechnya may weaken Gen Maskhadov's position even further. Already there are signs that the military action has served to shift the support of many Chechens from him to the rebels.
A statement yesterday by the Chechen Vice-Premier, Mr Kazbek Makashev, emphasises the danger involved.
"Russia has openly started a war against the Chechen Republic under the false pretext of aggression on the Chechen side," said Mr Makashev, who said he thought the Russian leadership was trying to solve internal political problems through the war in the Caucasus.
Some Russians subscribe to this theory also. The influential newspaper Izvestia has suggested that a war in the Caucasus could be followed by the declaration of a state of emergency in Russia as a whole and the cancellation of parliamentary and presidential elections due in December and next summer respectively, allowing President Yeltsin and his supporters to retain power.
This, if true, would appear to be an extremely risky strategy. War against a united Chechen population would, as has been shown, be extremely difficult to win and even if a military victory were achieved the resulting peace would be short-lived.
In the 1995-1996 war, up to 30,000 unarmed civilians lost their lives and the Chechen capital Grozny was almost completely destroyed. Hundreds of young, badly-trained and poorly-equipped Russian conscripts were killed in the early stages of the conflict and public opinion turned against Mr Yeltsin, whose support is now barely measurable in the opinion polls.
A new Russo-Chechen conflict could be even worse than the previous war, especially if it spread outside Chechnya and Dagestan into other areas of the volatile region. The Ingush, a people closely related to the Chechens, have begun to stop and search vehicles entering their republic from Chechnya. In Vladikavkaz, the capital of the autonomous republic of North Ossetia, all police and military posts have been put on a state of alert. The semi-official ITAR-TASS news agency has reported that the 99th Don Division of Russian interior ministry troops has begun to seal off the 284 km administrative border between North Ossetia and the republics of Chechnya and Ingushetia.
Special attention, the agency reports, has been given to the Mozdok district of North Ossetia, directly bordering Chechnya, which houses a section of the oil pipeline between Baku on the Caspian and the Russian port of Novorossiisk on the Black Sea.
The Caucasus mountains are higher than the Alps, and secret routes through remote forests and valleys have been used to hide hundreds of western hostages who have been kidnapped. The volatility of the area is such that almost every sector has been involved in unrest since the dismantling of the Soviet Union at the end of 1991. Azerbaijan and Armenia were involved in a protracted war over the disputed territory of Nagorno Karabakh, while South Ossetia tried to break away from Georgia.
Abkhazia, an extremely beautiful region along the Black Sea coast, actually did break away from Georgia in a bloody war in which Russian troops were alleged to support the separatists. Ethnic Georgians were driven from their homes and the Abkhaz people, once only 18 per cent of the population, are now the only ethnic group of any size in the territory.
Dagestan, with its dozens of indigenous nationalities as well as significant ethnic Russian and ethnic Azeri populations, is potentially even more unstable than any other area in the entire region. A full-scale war there and in Chechnya could be far more serious than any previous conflict.
President Yeltsin yesterday gave his generals a tongue-lashing for their failure to defeat Islamist rebels in Dagestan. He also criticised them strongly for allowing a car bomb to destroy a military apartment block in the Dagestani town of Buynaksk on Saturday last. By yesterday evening the death-toll from the blast had reached 64, many of them women and children.