Monday saw Azeri and Armenian forces exchange heavy artillery fire, with each accusing the other of starting the hostilities Sunday. Observers called the latest fighting over Nargono Karabakh, an enclave inside Azerbaijan but run by ethnic Armenians, the worst since the 1990s.
Witness reports put the number of dead, including civilians, at more than 20 and at least 100 wounded.
People watch TV in a bomb shelter in Stepanakert, the capital of the breakaway Nagorno-Karabakh region, in this picture released Sept. 28, 2020. (Foreign Ministry of Armenia/Handout via Reuters)
Turkish President Recep Tayyip Erdogan was quick to voice support for Azerbaijan, labeling Armenia "the biggest threat to peace in the region." The Turkish leader called on "the entire world to stand with Azerbaijan in their battle against invasion and cruelty."
The Armenian foreign ministry on Monday said Turkish military "experts" were "fighting side by side with Azerbaijan." Turkish government officials declined to comment on the accusations.
"Turkey troops will not be on the front line, Azeri forces don't need them," said Turkish analyst Ilhan Uzgel. But Uzgel says Ankara remains Baku's key military ally.
"Turkey is already supporting Azerbaijan militarily," he said, "through technical assistance through arms sales, providing critical military support, especially in terms of armed drones and technical expertise. The line for Turkey's involvement, is Russia's involvement; actually, that is a red line for Turkey. Turkey doesn't want a direct confrontation with Moscow."
An image from a video made available on the website of the Azerbaijani Defence Ministry on Sept. 28, 2020, allegedly shows Azeri troops conducting a combat operation during clashes between Armenian separatists and Azerbaijan in Nagorno-Karabakh.
Moscow is a vital supporter of Yerevan, and maintains a military base in Armenia.
The Russian foreign ministry on Monday called for Armenia and Azerbaijan to exercise restraint.
"Armenian-Russian relations are firm and solid," said Dr. Zaur Gasimov, a Russian affairs expert at Germany's Bonn University. "Now, having faced with casualties on the front line, Yerevan would search for more support from Moscow."
Ahead of Sunday's outbreak of fighting, Baku had accused Moscow of emboldening Yerevan with significant arms shipments since July.
"500 tonnes of military cargo has been delivered to Armenia. Let us be clear, from Russia," said Hikmat Hajiyev, head of Azerbaijan department of foreign affairs, in a briefing to foreign journalists in Turkey earlier this month.
Hajiyev highlighted the significance of Turkey’s military assistance. "We have seen firm and strong support of Turkey to Azerbaijan. Annually, we have 10 joint military exercises covering land troops, anti-terror special forces operations, and air force exercises."
In what observers interpreted as a message to Armenia, Turkish fighter jets carried out an exercise in Azerbaijan shortly after Armenian and Azeri forces clashed in July.
July's fighting in Azerbaijan's Tovuz region was close to crucial energy pipelines that serve Turkey, causing alarm in Ankara.
"This is a very core security issue for Turkey for energy security," said a senior Turkish energy ministry official speaking to journalists on the condition of anonymity. The official said Turkey "will take any relevant measures" to continue receiving energy deliveries from Azerbaijan.
Ankara has long supported Baku in its efforts to retake Nagorno-Karabakh, and Erdogan on Monday asserted that if Armenia immediately leaves the territory that he said it is occupying, the region will return to peace and harmony.
A view of a house said to have been damaged in recent shelling during clashes between Armenian separatists and Azerbaijan over the breakaway Nagorny Karabakh region, Sept. 28, 2020. (Handout Photo from Armenian Foreign Ministry)
Restoring Azeri control over Nagorno-Karabakh has the strong support of Turkish nationalists, a critical political base for Erdogan.
"Two nations, one people" is a popular mantra used by Baku and Ankara to describe the countries' relationship.
Armenian separatists seized Nargono Karabakh from Azerbaijan in a bloody 1990s war that killed an estimated 30,000 people.
Turkey appears poised to deepen its cooperation with Azerbaijan, analysts say.
"But it's quite a risky area. The Caucasus, it's one of Russia's near abroad, the Caucuses is part of Russian area of influence. They may not tolerate Turkish Azerbaijani military action against Armenia that results in heavy Armenian losses. If Turkey and Azerbaijan are planning to have a huge success through military means, that could put Turkish Russian relations at serious risk."
In recent years, Ankara and Moscow have deepened their relationship, cooperating in Syria and building trade ties that even extend to the purchase of sophisticated Russian military hardware.