By Jonathan Marcus
BBC Diplomatic correspondent
Russia's military intervention in Georgia has inevitably had a dramatic impact on the region.
The impact of Georgia's crisis will be played out far beyond Tbilisi
But the implications of its decision to unilaterally re-draw Georgia's boundaries by recognising the independence of the two separatist enclaves of Abkhazia and South Ossetia go way beyond the Caucasus - the ripples spreading into Turkey, the wider Middle East and beyond, reaching as far as the Caribbean.
The crisis has given an added boost to Turkey's efforts to become a significant diplomatic player in the region.
Turkey is a key member of Nato, though it also has important trading ties with Russia.
As a neighbour of Georgia it does not want to be precipitated into an unwanted confrontation with Moscow.
The Turkish government's efforts to conclude a Caucasus Stability and Cooperation Pact - something that has already taken the Turkish president on an unprecedented visit to his country's historical enemy, Armenia - are an effort to improve the climate in an often tense region.
The wider Middle East is already reacting to events in Georgia.
Israel appears to be fundamentally re-thinking its military ties to Tbilisi, concerned that these might encourage Russia to retaliate by making advanced weapons sales to Syria.
The Syrians have rushed to Russia's support, perhaps hoping to resurrect the close Cold War relationship between Damascus and Moscow.
Mr Medvedev is playing it tough but Russia does not seek a new Cold War
Even before the Georgia crisis erupted, Russia - angered at US missile defence plans in central Europe - was sending signals that it might step up military ties with Cuba.
Now, in the wake of US naval deployments to the Black Sea, Moscow is despatching one of its largest warships - a nuclear-powered cruiser - accompanied by a small flotilla, to the Caribbean for exercises with the Venezuelan Navy.
The message to Washington is clear - if you meddle in what we see as our backyard, the Russians are saying, then we will meddle in yours.
It all sounds like the makings of a trailer for a new Cold War drama.
But to some extent that would be to mis-read the signals.
Some may call it posturing, but it is posturing to a purpose. Messages are indeed being sent.
All the indications are - at least for the moment - that Russia is not intending to recreate the global struggles of the Cold War era.
It has so far refused sensitive arms sales to Syria, for example.
And many experts believe that Russia's chief aim in all of this is to assert itself closer to home, to draw strict limits to Nato's further expansion.
Further political battlegrounds lie ahead - most immediately in Ukraine where the events in Georgia have already worsened existing political divisions between those who look to the West for the future and those who look towards Moscow.
The European Union's decision, this week, to offer Ukraine closer relations but not a clear path to future membership highlights the delicacy of the diplomatic challenges facing Western nations as they struggle to respond to a newly resurgent Russia.
Europe at one and the same time wants to draw Ukraine "Westwards" in political terms, while not exacerbating the country's internal strife.
Stretched state department
Beyond Europe, the stakes are even higher.
What price now a new UN Security Council resolution bringing in any kind of tougher sanctions to roll back Iran's nuclear programme?
If the current atmosphere between Washington and Moscow is anything to go by then such a resolution may be a dead-letter.
Uncomfortable juggling? Even Ms Rice has struggled to cope
As the Bush Administration seeks to polish up its foreign policy legacy during its closing months in office, it can expect no help from Moscow.
Was Russia mishandled by the Bush administration, or was it simply given insufficient attention?
That will be for the historians to judge.
But, in a sense, it is clear that the Georgia crisis - like so many other aspects of this administration's performance abroad - has been inextricably bound up with the Iraq crisis.
It was Georgia's willingness to provide troops for operations in Iraq that established its military relationship with Washington in the first place and fixed its image as an out-post of democracy in Washington's collective mind.
And it may also be the extraordinary demands of dealing not just with the conflict in Iraq, but that in Afghanistan too, that meant that even a state department headed by a Russian expert in Condoleezza Rice was unable to give relations with Moscow sufficient time.