Behind the hostilities in South Ossetia are two nations that have long been spoiling for a fight.
Russia is eager to show it is boss in the region and US-backed Georgia is determined to prove it can stand up to its huge neighbour.
With Vladimir Putin in Beijing for the Olympic opening ceremony, Georgia may have been betting it could pounce on an opportunity to quickly wrest control of its breakaway province as the world's attention was fixed on China.
But the gamble may be backfiring: Washington will not endorse Georgia's power play and Moscow's counter-offensive has brought the two sides into a fight it will be hard for Georgia to win.
The conflict has great strategic importance because it pits one of Washington's staunchest allies in the war on terror against Russia, a re-emerging superpower with vast energy reserves that is showing growing eagerness to assert its will on the international stage.
Georgia has about 2,000 troops in Iraq, making it the third-largest contributor to coalition forces after the US and Britain.
It is aggressively lobbying to join Nato, a campaign that has infuriated a Kremlin loath to see its former vassal state slip further away from the former Soviet sphere of influence.
However, one analyst suggested that Georgia's unexpected assault Thursday may have been rooted as much in a sense that its Nato bid was faltering as in antagonism with Russia.
Earlier this year, Nato quashed Georgia's drive to get a so-called "road map" for alliance membership amid alarm that President Mikhail Saakashvili was backtracking on democracy with his violent suppression last year of opposition rallies.
Although Georgia got assurances that it could eventually join, "this pushed Georgia into a philosophy of self-reliance, the idea that Georgia will be able to regain breakaway entities only by its own means," said Nicu Popescu of the European Council on Foreign Relations.
"The elephant in the room behind this whole story is Georgia's Nato prospects," he said.
South Ossetia tensions bubbled up on August 1 with the outbreak of shooting and erupted into full-fledged combat yesterday. Georgia's withering artillery barrage came just hours after Mr Saakashvili declared a unilateral cease-fire ahead of negotiations set for the next day - and the separatists reportedly agreed to follow suit.
If Georgia violated its own cease-fire, it could be a crushing blow to its drive to integrate with the West.
Although the United States and other Nato members have sent substantial aid to build up Georgia's once-shabby military, diplomats often have shown clear discomfort with Mr Saakashvili's headstrong ways.
But if South Ossetia wrecked the brief truce, perhaps seeing the cease-fire offer as weakness, the separatists and more particularly their patrons in Moscow could be in trouble.
The West, already deeply concerned about Russia's recent rising military assertiveness, is likely to see Russia's involvement as naked aggression and its frequent calls for peace as disingenuous.
South Ossetia was trouble waiting to happen for years a "frozen conflict" with tensions building just below the surface.
Georgia's assault may have been a go-for-broke move by a country that felt it was out of options amid Russia's growing dominance in the region.
Or South Ossetia's separatists may have provoked Georgia once too often, in effect calling in the artillery assault on their capital.
A grudging cease-fire that ended a separatist war in 1992 left the region mostly under control of an internationally unrecognised government, but containing areas held by Georgian forces.
South Ossetia longed to be incorporated into Russia, whose province of North Ossetia contains their ethnic brethren. Georgia rejected the prospect: Ceding the territory would bring Russia to within 50 miles of the Georgian capital.
Negotiations were sporadic, often foundering on who should participate. Clashes broke out, especially near the South Ossetian capital Tskhinvali, which is in a pocket nearly surrounded by Georgian-held territory.
Tensions rose markedly this year after South Ossetia basked in Kosovo's independence, calling it an international precedent that legitimised its own refusal to remain part of Georgia.
Moscow boosted ties with the separatist government and repeatedly denounced Mr Saakashvili's push to join Nato.