Armenian separatists in Nagorno-Karabakh have, after three decades of struggle, agreed to disarm, dissolve their government and reintegrate with Azerbaijan after Baku seized back control in late September.
The collapse of the breakaway statelet could shift the balance of power in the region and has left Yerevan facing a raft of geopolitical concerns.
- Russian 'double-deals' -
Nearly all of Karabakh's estimated 120,000 residents have now fled, with Yerevan accusing Azerbaijan of conducting a campaign of "ethnic cleansing" to clear the territory.
But Baku has denied the claim and publicly called on Karabakh's ethnic Armenian population to stay and "reintegrate" into Azerbaijan.
Russia, a long-standing ally of Armenia, insisted those fleeing the territory had nothing to fear, with Kremlin spokesman Dmitry Peskov saying: "It's difficult to say who is to blame (for the exodus). There is no direct reason for such actions."
Armenian Prime Minister Nikol Pashinyan has criticised the Russian peacekeeping force in Nagorno-Karabakh for failing to intervene during Baku's lightning offensive, which Moscow has denied.
Nearly 2,000 Russian peacekeepers were deployed to the mountainous region in 2020 as part of a ceasefire deal it brokered between Azerbaijan and Armenia that ended six weeks of fighting.
But Russia gave a lukewarm response to the announcement last week that the ethnic Armenian statelet of Karabakh would cease to exist at the end of the year.
"We have taken notice of this and are closely monitoring the situation. Our peacekeepers continue to assist people," Peskov said.
Analysts say that Russia has chosen to side with the growing power of oil-rich Azerbaijan over its sparsely populated and diplomatically isolated historic ally Armenia.
Moscow also warned last week that Armenia's decision to join the International Criminal Court (ICC), which has issued an arrest warrant for President Vladimir Putin, would be "extremely hostile".
But Russia could still have an upper hand in the region, experts have said.
"The only framework agreement still in place, even though most of its provisions lie in tatters, is the trilateral ceasefire deal brokered by Russia on November 9, 2020," said Carnegie Europe expert Thomas de Waal.
"One of its provisions is for border guards from Russia's FSB security service to protect the transport corridor across Armenia to Nakhchivan -- a distasteful prospect given Russia's war in Ukraine," he added.
- Turkey-Azerbaijan alliance -
A complex hangover from the Soviet era, the Azerbaijani exclave of Nakhchivan, a landlocked autonomous republic, does not share a border with Azerbaijan but has been tied to Baku since the 1920s. It is located between Armenia, Turkey and Iran.
Some experts believe that Azerbaijani President Ilham Aliyev could now seek to launch operations in southern Armenia to create a territorial link with Nakhchivan.
Allies Turkey and Azerbaijan had said in June they wanted to step up efforts to open a land corridor linking Turkey to Azerbaijan's main territory via Nakhchivan and Armenia, a longstanding and complex project.
A few days after Azerbaijan's lightning offensive in Nagorno-Karabakh on September 19 and 20, Aliyev met his Turkish counterpart Recep Tayyip Erdogan in the exclave.
Aliyev recently referred to southern Armenia as "Western Azerbaijan" and in December said Azerbaijanis "must be able to return to their native lands".
He went further in February 2018, when he told a press conference: "Yerevan is our historic land... We Azerbaijanis must return to our historic lands."
The alliance between Turkey and Azerbaijan, both mainly Muslim, is fuelled by a mutual mistrust of largely Christian Armenia.
The latter harbours hostility towards Ankara over the massacres of some 1.5 million Armenians by Turkey during the dying days of the Ottoman Empire.
More than 30 countries have recognised the killings as genocide, although Ankara fiercely disputes the term.
- Iran unknown -
Another major geopolitical player in the region is Iran, which has commercial interests in Armenia's future.
Iran sees Armenia as its commercial gateway to the Caucasus and therefore "does not want to see the border move" to favour Azerbaijan, said professor Taline Ter Minassian of France's National Institute for Oriental Languages and Civilizations.
The reasons are also geostrategic, as Azerbaijan has for years been drawing nearer to Israel, Tehran's arch-enemy.
Israel accounted for almost 70 percent of arms sales to Azerbaijan between 2016 and 2020, according to the Stockholm International Peace Research Institute.
The French Centre for Intelligence Research has said that Israel has built "several electronic intelligence stations" in Azerbaijan.
Azerbaijan's key ally Turkey is also a member of NATO, the US-led military alliance with which Iran is also at loggerheads.
In the absence of a convincing Western commitment to Armenia, its "only protection so far has been Iran", said Jean-Louis Bourlanges, chair of the French Foreign Affairs Committee.
"It's a very fragile and worrying guarantee," he added.