[This article is from the Telegraph. It is not clear that the Russian government was actually behind this attack; it could have been rogue Russian military units. However, there are existing tensions between the two countries. If Russia is behind this, it represents a significant escalation of the conflict. Russian officials have so far denied that this was done on government orders.]
Despite categorical denials from the Kremlin, Georgia seems convinced that the missile which struck a vegetable field near Tbilisi last night was fired by a Russian warplane.
It is not the first time that there have been reported violations of Georgian airspace this year.
In March, Russian helicopters were accused of opening fire in the remote Kodori Gorge, close to the lawless breakaway region of Abkhazia, which is backed by Moscow.
A report by United Nations observers concluded that it was unclear who was behind the incident. If it is shown that yesterday's attack was carried out by the Russian military, it would represent a significant escalation in the diplomatic crisis between the two countries.
Georgia has already called the strike "an act of aggression". The question is why Russia would carry out so provocative an attack.
There is no doubt how serious is the rift between the two countries since Mikhail Saakashvili, the westernizing president, was swept to power in the Rose Revolution of 2003.
Russia has deeply resented its loss of influence in the country of Stalin's birth and is determined to halt Mr Saakashvili's ambitions for Nato and EU membership.
Moscow showed its displeasure by banning exports of Georgian wine and mineral water, vital sectors of an economy still heavily dependent on Russia.
Tensions erupted last September after Georgia expelled four Russian officers it accused of espionage. The Kremlin's excessive reaction raised eyebrows around the world. Moscow withdrew its diplomats from Tbilisi, severed trade, transport and postal links and deported thousands of Georgians living in Russia.
With a fierce anti-Georgian campaign being waged in the Russian press, some commentators suggested that a group of Kremlin hardliners were intent on provoking a military confrontation to provide an excuse to change the constitution and allow Vladimir Putin to stay in power.
The president is due to step down next March after completing his second term.
Alexei Malashenko, an expert on the Caucasus at the Moscow Carnegie Centre, said it was possible that this faction had ordered the firing of a dummy missile in a bid to fuel the crisis.
But he and other analysts said it was more likely that the missile attack could have been carried out by local Russian army units without the knowledge of the Kremlin.
The location of the air strike was close to South Ossetia, another Moscow backed breakaway region. Georgia and Russia have been at loggerheads over the tiny region — which is about the size of Suffolk — for years.
Tbilisi has accused Moscow of arming the rebels and firefights between separatists and Georgian soldiers have increased since 2004.
There have been signs, however, that Russia is finally willing to negotiate a settlement. Moscow has opposed the West's backing for independence of Kosovo, arguing that Serbia's territorial integrity should be inviolable and has threatened to veto a UN resolution that backs Pristina's position.
As a result, the Kremlin has had to temper its support for Georgia's breakaway regions or risk being accused of hypocrisy. But for Russian military units stationed in South Ossetia as peacekeepers and their commanders across the border in southern Russia, a peace accord would be highly undesirable.
As it has descended into lawlessness, South Ossetia has become a haven for smugglers and counterfeiters. According to western diplomats, a significant proportion of the fake dollar bills in circulation on America's east coast were manufactured here.
According to analysts, those profiting the most are Russian officers — many of whom hold posts in the South Ossetian administration.