Russia has warned it will retaliate if Georgia uses force against its breakaway regions of Abkhazia and South Ossetia. BBC Russia analyst Steven Eke explains the background to the conflict between the two countries.
South Ossetian separatists seek Russia's protection
The leader of Abkhazia, Sergei Bagapsh, has said the co-existence of his region and Georgia once more in a unified state is impossible.
This was an unequivocal response to a call from Georgian President Mikhail Saakashvili to the local population to resist what he called "outrageous external forces" - by which he meant Russia.
Georgia has rejected Russian accusations that is has bolstered troop numbers in the conflict zone in order to create a bridgehead for an attack on Abkhazia.
The speaker of the Georgian parliament, Nino Burjanadze, has branded Russia's decision to deploy extra peacekeepers there as "a direct attempt to annex Georgian territory".
The Georgian-Abkhaz war in the early 1990s erupted as a result of long-running inter-ethnic tensions. It was an extremely vicious conflict, in which both sides carried out ethnic cleansing, mass killings and wanton destruction of property.
An agreement reached by CIS (Commonwealth of Independent States) heads of state in August 1994 provides for some 2,500-3,000 CIS, overwhelmingly Russian, peacekeepers to be stationed in the conflict zone.
There is also a smaller UN-mandated observer mission, consisting of military observers and international police.
Georgia does not believe the Russian peacekeepers are neutral. Instead, Tbilisi alleges, they are an actual party to the conflict, supporting the Abkhaz separatists.
The situation is complicated by Russia's policy of offering a fast track to Russian citizenship to large numbers - more than two-thirds - of Abkhazia's population.
This allows Russian Foreign Minister Sergei Lavrov to announce that Russia will use whatever means necessary to defend "its" citizens.
Tension between Russia and Georgia is nothing new. Previous low points have included Russia imposing trade sanctions and energy blockades.
Now, Georgia says it will block Russia's bid to join the World Trade Organization.
The source of the current, ominous spat is, however, the situation in Abkhazia.
The major catalyst seems to have been the announcement from Moscow on 16 April that it was lifting economic sanctions and boosting official links with the separatist administration in Sukhumi, the Abkhaz capital.
It remains unclear whether this was a prelude to full Russian recognition of Abkhazia's self-declared independence. After all, Russia clearly condemns separatism in its own territory, as well as abroad, in places like Kosovo and Tibet.
Russian officials, from President Vladimir Putin down, warned that the recognition by many Western nations of Kosovo's, unilaterally declared, independence would serve as a template for its own actions in the pro-Russian, separatist regions of the former USSR.
Tensions were further exacerbated by the apparent shooting down of an unmanned Georgian drone by a Russian air force MiG-29. Russia denies involvement, but says the drone itself was illegal.
President Saakashvili has made restoring Georgia's territorial integrity a priority in his political project.
Just months after coming to office, he oversaw the return of another formerly separatist region - Ajaria - to central control. He pledged then that the entire country would be "reunified".
However, many conflict resolution experts doubt whether he will succeed in the case of Abkhazia. Its people, an ethnic group distinct from Georgians, do not want to live under Georgian rule, they say.
And it might just be too late. Attracted by a stronger and richer Russia, many say Abkhazia is now irrevocably on the path of assimilation with Russia.