The Independent has published a useful summary of events in the Russian invasion of Georgia. Though the article suffers here and there in its attempts to be "even-handed", it does give a fairly clear picture of the hours leading up to the Russian assault. Excerpt:
On 7 August, the day before the Olympics began, the Georgian negotiator, Temuri Yakobashvili, went to the South Ossetian capital of Tskhinvali for direct talks with the de facto separatist leader and a Russian envoy. Yakobashvili recalls that Tskhinvali already looked like a ghost town. But the Russian diplomat, Yuri Popov, failed to show up for the meeting at a Russian military base, saying that his car had a flat tyre. "Can't you change the tyre?" the incredulous Georgian negotiator asked the Russian who was supposed to be chairing the talks. No, he replied, as he did not have a spare.
Then, the South Ossetian leader Eduard Kokoity failed to show up. Yakobashvili asked the Russian general who headed the joint peacekeeping commission what to do, and was told: "Declare a ceasefire." So, that night at 7 pm, Saakashvili went on television and declared a unilateral ceasefire. But by that time, Georgian tanks and troops were on the move.
At 10.30pm, two Georgian peacekeepers were killed and six injured when the rebels opened fire on Georgian positions. But the attack that prompted Georgia's full-scale attack, at about midnight on 7 August, was a bombardment of the villages of Tamarasheni and Kurta, close to Tskhinvali.
Then, the Georgians say, came the "tipping point". They say the US showed them satellite photographs of 150 Russian tanks entering the Roki tunnel, although the Georgians have refused to provide such evidence. The Russians insist their build-up through the tunnel came only after the Georgians attacked Tskhinvali, killing 15 Russian peacekeepers. "This was a heavy armoured Russian column, moving slowly, on very rugged terrain in the highest mountain range in Europe," says Prime Minister Lado Gurgenidze of Georgia. "Think how many hours of preparation, assembly, then marching, it would take for that column, moving at that speed on rugged terrain, to be at the Kurta bridge at six in the morning. If that isn't a premeditated invasion, I don't know what is." They were regular Russian troops, not peacekeepers, heading to Tskhinvali.