Tensions are once again escalating between Armenia and Azerbaijan, six months after a ceasefire ended the second Nagorny Karabakh war.

Yerevan has accused Baku of deploying hundreds of troops on the eastern border of Armenia near the Black Lake and the village of Kut in the Syunik and Gegharkunik regions

It first announced that more than 250 Azerbaijani military personnel had entered Armenian territory on May 12, numbers officials say have since risen to between 500 and 600.

The Armenian defence ministry said that the incursion was under the pretext of “clarifying the borders,” which they interpreted as an attempt to provoke hostilities.

“The clear evidence of this is a recent statement of the Azerbaijani president Ilham Aliyev saying that if Armenia was unwilling to open a corridor to [the enclave of] Nakhichevan, Baku would do it by force,” acting prime minister Nikol Pashinyan told an emergency meeting in parliament on May 14. “And, the day before the incident, large-scale military exercises were launched on the border in Azerbaijan.”

A rapid solution of the border crisis will help Pashinyan improve his performance in the early parliamentary elections scheduled for June 20.

His standing has been significantly downgraded since the defeat over Karabakh, and to defuse the political crisis he formally resigned in April and agreed to fresh polls.

Armenia has demanded the immediate and unconditional return of Azerbaijani forces to their initial positions, insisting that these sections of the border are their sovereign territory. There has been a partial mobilisation of forces in Armenia due to the escalation, with some units of the Yerkrapah Volunteer Union already deployed to the front line.

Following last year’s six-week war, the parties began using Soviet-era maps to define their borders. Negotiations on this issue began on May 12, but so far without success.

According to Yerevan, the situation is particularly fraught since both sides have concentrated a large number of forces and military equipment on the border. It asked the Russian-led Collective Security Treaty Organisation bloc (CSTO) for military support in the face of these renewed tensions.

“Without any doubt, after involvement of the CSTO, the problem around the Black Lake will be resolved in favor of Armenia,” Armen Grigoryan, security council secretary told reporters on May 12.  after the meeting of the Security Council on May 12. “The enemy understands that with the help of Russia we will restore the army very soon and that is why it is taking such steps.”

However, no support has so far been forthcoming.

“Armenia’s appeal to the CSTO is actually an appeal to Russia, since no one in Armenia believes that the armed forces of Tajikistan or Belarus will be deployed to Armenia to protect its borders,” said Alexander Iskandaryan, director of the Caucasus Institute. He was sceptical about any direct Russian military involvement to defend Armenia’s border.

“For the simple reason – Azerbaijan is important for Russia. Moscow will try to defuse the tension through negotiations, wishing not to use any extreme measures,” he concluded.

Yerevan has close ties with Moscow, with a unified air defence system and Russian troops deployed in Armenia. Moreover, Russia is supporting the rebuilding of the Armenian army after the war and has opened two strongholds of the 102 Russian military base in the Syunik region.

Their commander, General Alexander Dvornikov arrived in Armenia for talks on May 14.

“The visit of Alexander Dvornikov to Armenia is a very important signal and is directly related to the situation on the Armenian-Azerbaijani border,” said Andranik Kocharian, chairman of the standing committee on defence and security. “We hope that with the help of Russia and the CSTO, Azerbaijani troops will retreat to their initial positions.”

The local media reported on the transfer of forces from the Russian military base to the Syunik and Gegharkunik regions, reports which the Armenian authorities did not deny.

The protection of the Syunik region is of particular importance, since it borders Iran, one of Armenia’s two existing gateways to the outside world.

“It is Syunik that enhances Armenia’s role in the region and turns it into a factor,” said analyst Tatul Hakobyan.

But Russia has so far focused on diplomatic mechanisms to address the escalation. CSTO secretary general Stanislav Zas has held regular telephone conversations with the heads of the Armenian foreign and defence ministries, while on May 19, Russian President Vladimir Putin spoke to both Pashinyan and Azerbaijan’s president Ilham Aliyev.

Moscow also proposed to act as an intermediary between Yerevan and Baku in the border delimitation process. Armenia agreed, on condition Azerbaijani troops first withdraw from its territory.

Some have warned, however, that this could have dire consequences for Karabakh.

“Delimitation of the border with Azerbaijan, without specifying the status of Karabakh, means the recognition of the Azerbaijani borders and the closure of the Karabakh page,” said Edmon Marukyan, leader of the opposition Bright Armenia party. “In this case, Karabakh might face the fate of Nakhichevan, that is, Armenians leaving the region. I hope the Armenian leadership understands the implications of this dangerous idea and will take measures.