A regional conflict is rapidly reaching an "irreversible point" where major military powers including Russia will be sucked in which is almost certain to lead to even more bloodshed, a veteran diplomat has warned.
As many as 5000 people are now thought to have perished in four weeks' worth of fighting between the central Asian nations of Armenia and Azerbaijan.
Which country has possession of a thin strip of land could be all that stops the battle from becoming a far wider war. Now Moscow is reported to have made its first clear move at picking a side.
The two fractious neighbours are in a deadly squabble centred on the mountainous region of Nagorno-Karabakh. It is internationally recognised as being part of Azerbaijan but has been governed for decades by ethnic Armenians.
Armed conflict broke out in late September after Azerbaijan, widely thought to be backed with weapons and manpower from Turkey, began shelling the disputed territory in an effort to recapture it.
Since then, both sides have been accused of bombing positions and cities across the front line.
Diplomatic efforts have, so far, proved fruitless.
People try to remove car tyres from a car shop on fire after shelling by Azerbaijan's artillery during a military conflict in Stepanakert, the separatist region of Nagorno-Karabakh. Photo / AP
A Russian-brokered ceasefire was broken within a day; a further agreement to down arms collapsed within hours; last week a US-backed deal to stop the fighting only lasted a few minutes.
Carey Cavanaugh is a former US ambassador who led peace efforts in 2001 over exactly the same intractable dispute. He said if current talks involving Turkey, Russia, the US and France did not achieve real results, the fighting was almost certain to escalate.
"Outside nations, specifically Turkey and Russia may well then enter the fray," he wrote in an article for the Financial Times.
"The result would be a potentially staggering level of death, destruction and suffering".
Already, Iran, which borders on both warring nations, has warned that if any more shells inadvertently land on its territory it will be forced to become involved.
Historically both Christian Armenians and Muslim Turks from Azerbaijan called Nagorno-Karabakh home.
However, since a war in the 1990s that killed 30,000, most of the area has been populated and governed by ethnic Armenians who call it the Republic of Artsakh.
Not a single nation recognises Artsakh – not even Armenia – but it is supported by the Armenian government.
For decades, an uneasy truce prevailed. But no longer.
Cavanaugh has said the key reason the conflict has flared up once again is Turkey's backing of Azerbaijan. Its weapons have helped it claw back some land.
"This external support and relative military success has generated broad public support in Azerbaijan for the war effort."
An instructor helps a volunteer soldier practise with a sniper rifle at a military base near the front line during the military conflict in the separatist region of Nagorno-Karabakh. Photo / AP
On Wednesday, Azerbaijan accused Armenia of killing 21 people and wounding dozens in a missile strike near the frontier, the deadliest reported attack on civilians in a month of fighting over the disputed region.
Armenia has denied carrying out the attack, the second in two days that Azerbaijan says killed civilians in the Barda district.
Yerevan, in turn, accused Azerbaijani forces of deadly new strikes on civilian areas of the disputed region, as both sides claim the other is targeting civilians after weeks of fierce frontline clashes, reported news agency AFP.
The International Committee for the Red Cross said the shelling of urban areas was "appalling".
"These latest exchanges signal that the Nagorno-Karabakh conflict risks spiralling out of control," said the ICRC's regional director Martin Schüepp.
RUSSIA'S MOVE ON THIN STRIP OF LAND
Smoke rises during fighting between Armenian and Azerbaijani forces in the Karabakh mountains. Photo / AP
There are growing fears about what might happen if a thin strip of land known as the Lachin corridor is overrun by Azerbaijan forces.
The pass links Nagorno-Karabakh to Armenia proper and is a crucial supply line for everything from food to weaponry.
It's been reported Azerbaijan forces are closing in on the strip.
"If this corridor is severed the conflict will stand on the brink of a humanitarian disaster," said Cavanaugh, who is a professor of diplomacy at the University of Kentucky.
It could lead to the ethnic Armenians in Nagorno-Karabakh becoming trapped and would likely force Armenia to crank up its military response.
"This could lead Moscow to act in accordance with its mutual defence pact with Armenia which in turn could elicit the entry of the Turkish military."
Previously, Russia has stood on the sidelines seemingly unwilling to pick sides between two nations that were once part of the USSR.
Russian President Vladimir Putin had said its defence agreement with Armenia would only come into effect if that country's territory was threatened. As Nagorno-Karabakh is not recognised by Armenia, he indicated Moscow had no reason to intervene.
But it looks like Russia is now taking sides as the fighting gets closer to Armenia's internationally recognised borders.
A Russia news photographer is reported to have seen a Russian camp set up at an Armenian village close to the Lachin corridor. It's only a few tents and a Russian flag but it's a powerful sign to approaching Azerbaijan forces not to cut off the pass, reported central Asian news service Eurasianet. Moscow is also thought to be supplying weapons to Yerevan.
A photo by TASS photographer Sergei Bobylev shows a Russian field camp set up near Tegh, close to the Lachin pass which connects Nagorno-Karabakh with Armenia. Azerbaijani forces have made advances towards the pass in recent days.
The overall situation isn't helped by the US being distracted by the election campaign and France and Turkey in a war of words over the treatment of Muslims following the beheading of a teacher in Paris in a terror attack.
Writing for think tank the Australian Strategic Policy Institute earlier this month, international relations expert Mohammed Ayoob said there was the "alarming" prospect of the conflict dragging in regional superpowers.
"Turkey has traditionally been a staunch supporter of Azerbaijan (while) Russia considers Armenia a strategic ally, but also considers Azerbaijan a strategic partner.
