By Robin Paxton and Gabrielle Tétrault-Farber
(Reuters) - A recent rallying cry by the ethnic Armenian leader of Nagorno-Karabakh contained a startling admission: enemy troops were no more than five kilometres (three miles) from the mountain enclave's second-largest city.
Emboldened by Turkish support, Azerbaijan has the upper hand in the bloodiest fighting in more than 25 years in the South Caucasus. In just over a month, it has retaken much of the land in and around Nagorno-Karabakh that it lost in the 1990s.
It now faces a difficult choice: advance on the symbolic city of Shusha - Shushi to Armenians - a staging post for an assault on the region's largest city, Stepanakert. Or sever Armenia's main supply corridor to the west.
But analysts say a third option - to consolidate military gains and return to the negotiating table from a position of greater strength - might be the smartest move as winter draws in.
"It's clearly Azerbaijan's war to lose," said Michael Kofman, director of the Russia Studies Program at CNA, a U.S.-based research body. "Armenia's position is very precarious."
Azerbaijan's success on the battlefield gives it less of an incentive to strike a lasting peace deal, complicating international efforts to broker one. With three ceasefires already broken, analysts expect little from talks in Geneva on Friday.
At stake is the fate of Nagorno-Karabakh and seven other regions that surround it. The territory is internationally recognised as part of Azerbaijan but populated and controlled by ethnic Armenians.
Nagorno-Karabakh's leader, Arayik Harutyunyan, on Thursday called on citizens to repel any attack on Shushi. The city is of cultural and strategic importance to both sides, perched on high ground just 15 km (9 miles) south of Stepanakert.
"If Azerbaijan were to take it back, Stepanakert would become like another Sarajevo," said Neil Melvin, director of international security studies at the RUSI think tank in London, referring to the city besieged during the 1990s Bosnian war.
From a military standpoint, however, analysts said a better tactic for Azerbaijan, and one likely to involve fewer casualties, would be a northward push on its western flank toward a key supply route linking Armenia and Nagorno-Karabakh.
Armenian defence ministry official Artsrun Hovhannisyan said this week that Azerbaijan had made an unsuccessful attempt to advance on Lachin, having already captured the region of Gubadli further south, severing Armenian access to the Iranian border.
"If Lachin is taken, that would be a strategic success for Azerbaijan and a catastrophe for the Nagorno-Karabakh defence forces," said Viktor Murakhovsky, a retired Russian army colonel and editor of a military magazine.
"It would be impossible (for Armenia) to deliver food, fuel and people there. In this case, the fall of Nagorno-Karabakh would be a question of time."
When the 1991-94 war ended, with around 30,000 killed, the Armenians had won control of Nagorno-Karabakh and seven surrounding regions, amounting to 13.6% of the de jure territory of Azerbaijan, according to Carnegie Europe.
Much of this land has been retaken in fighting since Sept. 27, possibly as much as 15% of Nagorno-Karabakh itself, according to Kofman - territory that he said Armenia "does not have the means to take back".
Tensions between the two sides had been building over the summer and spilled into direct clashes as the outside powers that have mediated in the past - Russia, France and the United States - were distracted by the COVID-19 pandemic, the upcoming U.S. presidential election and a list of world crises.
The biggest change since the 1990s is Turkey's influence in a region that was once entirely part of the Soviet Union.
"Turkish support for Azerbaijan is what makes this situation qualitatively different from all the previous conflagrations," said Alex Melikishvili, a principal research analyst at IHS Markit Country Risk.
He said the presence of Turkish F-16 fighter jets at a military airfield in Ganja, Azerbaijan's second-largest city, "represents a very tangible confirmation that the geopolitical balance in South Caucasus has changed."
Azerbaijan, rich in oil and gas, can also afford superior firepower. In September alone, it bought $77 million worth of military equipment from Turkey, including drones that afford it an aerial superiority absent in earlier conflicts.
"Money, not people, are at war," said Russian political analyst Dmitry Oreshkin. "The Armenians have archaic, practically Soviet weaponry while the Azeri forces are buying the most modern tanks and drones."
In the ascendancy, Azerbaijan has little military incentive to negotiate a ceasefire on terms that fall short of its demands for ethnic Armenian troops to agree to leave Nagorno-Karabakh.
A Russian defence pact with Yerevan extends only to Armenian territory outside the current conflict zone. Armenian Prime Minister Nikol Pashinyan told Reuters this month only a change in Turkey's stance could prompt Azerbaijan to halt military action.
Azerbaijan is potentially vulnerable, however, to counter-attack along overstretched supply lines through territory gained in the relatively flat and sparsely populated south. Combat further north, in mountains where ethnic Armenian troops are dug in, would also be harder.
"Eventually there will be a settlement, but that settlement will need to be between Russia and Turkey," said Kofman. "You can't return to the 'status quo'. What's been going on for the last 30 years is over."
(Reporting by Robin Paxton, Gabrielle Tetrault-Farber and Maria Tsvetkova; Editing by Andrew Osborn and Frances Kerry)