It looks, in retrospect, like a ruse that went badly wrong. After days of heavy skirmishing between Georgian troops and Russian-backed separatist militias in the breakaway republic of South Ossetia, Mikhail Saakashvili, the Georgian President, went on television on Thursday evening to announce that he had ordered an immediate unilateral ceasefire.

Just hours later his troops began an all-out offensive with tanks and rockets to “restore constitutional order” to a region that won de facto independence in a vicious civil war that subsided in 1992.

From that moment events began to spiral out of control. As the 70,000 citizens of a self-styled republic of 2,500 square kilometres (965 square miles) huddled in their basements, Georgian troops seized a dozen villages and bombarded the capital, Tskhinvali, with air strikes, missiles and tank movements that left much of it destroyed.

Major-General Marat Kulakhmetov, the commander of a small force of Russian peacekeepers in Tskhinvali, said: “Heavy artillery shelling conducted for several hours has practically demolished the town,” The South Ossetians used grenade launchers to hit back against Georgia’s heavy military vehicles, and appealed for help from Russia, the country that has propped up the impoverished republic despite Moscow’s official support for Georgia’s territorial integrity.

Times Archive, 1924: The revolt in Georgia

The movement against the Bolshevists is considered to be more than a mere rising. It is considered to be a war of independence

• Terrible reprisals

• Georgia and the Soviets

• Letter: The fate of Georgia

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• Russia turns the might of its war machine on Georgia

• Georgia on the brink

• Fait accompli that failed

Mr Saakashvili, who took office in 2004 promising to restore Georgian rule over South Ossetia, appeared to have misjudged Moscow’s resolve, perhaps calculating that Vladimir Putin would not dare to respond militarily while he was in Beijing for the opening ceremony of the Olympic Games.

In fact it was Mr Putin, not his presidential successor, Dmitri Medvedev, who was the first to react. Seizing on the reported deaths of at least ten Russian peacekeepers in the Georgian offensive, as well as the fact that 90 per cent of South Ossetia’s population have Russian passports, he declared that Georgia’s actions “will incur a response”.

President Medvedev, who has yet to emerge from Mr Putin’s shadow, subsequently declared: “I am bound to defend the lives and the dignity of Russian citizens no matter where they are situated. We will not allow their deaths to go unpunished.”

Upset by Georgia’s pursuit of Nato membership and angered by the West’s support for Kosovo’s unilateral declaration of independence from Serbia this spring, Moscow responded fast and with force. Russian fighter planes reportedly attacked military and civilian targets inside Georgia. Units of the 58th Army, including scores of tanks and armoured personnel carriers, rolled southwards across the Russian border into South Ossetia.

The Russian Defence Ministry said that it had sent reinforcements to help peacekeepers to prevent bloodshed. Volunteers from North Ossetia – part of Russia – and Georgia’s other breakaway region, Abkhazia, were also said to be streaming into South Ossetia. Lyudmila Ostayeva, 50, a civilian who had fled with her family from Tskhinvali to Dzhava, a village near the border with Russia, said: “I saw bodies lying on the streets, around ruined buildings, in cars. It’s impossible to count them now. There is hardly a single building left undamaged.”

Late yesterday reporters saw trucks ferrying scores of wounded Georgian soldiers away from South Ossetia. Georgian officials claimed that their air force had shot down at least five Russian warplanes, a claim that Moscow denied.

The International Committee of the Red Cross appealed for the opening of a humanitarian corridor to allow ambulances to evacuate the wounded from Tskhinvali. “Ambulances cannot move, hospitals are reported to be overflowing, surgery is taking place in corridors,” a spokeswoman said.

Mr Saakashvili compared the incursion of Russian tanks to the Soviet invasions of Afghanistan and Czechoslovakia. He said: “We have Russian tanks on our territory, jets on our territory in broad daylight.”

The Georgian President, Harvard-educated and staunchly pro-Western, ordered a full-scale military mobilisation, with reservists called into action, and issued urgent appeals for international support. He told CNN: “Russia is fighting a war with us in our own territory.”

Georgia is a vital conduit for the West’s oil and gas supplies. Nato is due to decide in December whether and when to offer Georgia membership, a decision that would be enormously complicated if it is in a state of war with its giant northern neighbour. There is a danger of the fighting in South Ossetia spreading to Abkhazia, and if Russia can impose its will on Georgia it will be encouraged to do so in other former Soviet republics.

The United States, the European Union and Nato all issued appeals for an end to the fighting, but on Thursday night Britain and the US blocked a Russian-sponsored UN resolution that called for an immediate end to bloodshed in Georgia-South Ossetia. British and US diplomats said that the proposal prejudiced Georgia’s sovereignty over South Ossetia, and should describe South Ossetia as a “region of Georgia”. The 15-nation Security Council was meeting again last night.

The road to violence

1991 Collapse of the Soviet Union

1992 South Ossetia votes for independence from Georgia in an unrecognised referendum. Hundreds die in violence. Russia, Georgia and South Ossetia create tripartite peacekeeping force

1993 South Ossetia drafts its own constitution

2002 Unrecognised president Eduard Kokoity asks Moscow to absorb South Ossetia into Russia

2004 New Georgian President Mikhail Saakashvili says he will return breakaway South Ossetia, Ajaria and Abkhazia to the fold

2006 South Ossetians vote for independence again

2007 Talks between Georgia and South Ossetia break down.

2008 South Ossetia asks world to recognise its independence

2008 Georgian bid to join Nato makes Russian parliament urge Kremlin to recognise South Ossetia and Abkhazia

2008 South Ossetia rejects a Georgian power-sharing deal

2008 Georgian troops clash with South Ossetian and Russian forces

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