MOSCOW - In late 2020, when Russian President Vladimir Putin brokered the end of a war in the Caucasus between Azerbaijan and Armenia, and placed 2,000 Russian peacekeeping troops between the two sides, it looked like a strategic masterstroke.

The deal gave Russia a military presence in one post-Soviet country, Azerbaijan, while deepening the reliance of another, Armenia, on Russia as a guarantor of its security.

It positioned Mr Putin as a peacemaker and seemed to affirm his claim to Russia’s rightful influence, as the only power capable of keeping stability throughout the former Soviet sphere.

Barely two years later, the conflict over the Nagorno-Karabakh region of Azerbaijan is heating up again.

Russia, distracted and weakened by the war in Ukraine, has not stepped in.

Defying the Russian presence, Azerbaijanis are testing whether Moscow is still able and determined to impose its will on other, smaller neighbours amid its struggles in Ukraine.

Since Dec 12, the mountain road linking Nagorno-Karabakh to Armenia has been blocked amid protests by Azerbaijani activists claiming to be opposing illegal mining operations in the area.

Azerbaijan’s government has endorsed the protests; Armenians say Azerbaijan engineered them and criticise Russian peacekeepers for not keeping the road open.

“It can be seen that Russia’s resources in the region are becoming limited,” said Farhad Mammadov, a pro-government analyst in Baku, the capital of Azerbaijan. “Russia is becoming weaker.”

The roadblocks are a new escalation in the bloody, decades-old dispute over an enclave home to tens of thousands of ethnic Armenians within Azerbaijan’s internationally recognised borders.

In Nagorno-Karabakh, supermarkets are stocked with little but alcohol and candy.

Supplies of diapers and basic medicine are so low that residents post on Facebook in search of them, according to Tatev Azizyan, a journalist.

Starting Friday, people will have to present ration cards to buy rice, pasta, buckwheat or sugar.

Russia’s invasion of Ukraine has reshaped relations around the globe, perhaps nowhere more clearly than on the boundary between Europe and Asia.

It has strengthened the hands of Turkey and Iran, now important sources of trade and weapons for Moscow, while undermining Russian influence in the Caucasus.

Armenia is part of the Russian-led military alliance of six post-Soviet countries, the Collective Security Treaty Organization, and hosts a Russian military base. But so far, the Kremlin, with its hands full in Ukraine, has not taken action to aid its ally.

“The whole concentration of attention on Ukraine makes the situation more fragile and gives a new opportunity to Azerbaijan to use force and be more aggressive,” Vahan Kostanyan, an adviser to Armenia’s foreign minister, said in a recent interview.

Armenia won a war against Azerbaijan over Nagorno-Karabakh in the early 1990s, giving it control of about 13 per cent of Azerbaijan’s total land area, including Nagorno-Karabakh. Azerbaijan won much of it back when it launched an offensive in 2020, taking advantage of its natural gas profits to buy superior weaponry from Turkey and Israel.

The recent war ended after 44 days with the ceasefire negotiated by Mr Putin, and Russian troops were deployed to protect the Armenians remaining in and around Stepanakert, the region’s biggest city, and the road connecting it to Armenia.

Now, some Armenians believe, Azerbaijan is intent on starving them out with the roadblocks.

“This is so that we leave our homeland,” Azizyan, the journalist in Armenian-populated Nagorno-Karabakh, said in a phone interview. “That is their goal.”

Azerbaijani President Ilham Aliyev said last week that “whoever does not want to become our citizen, the road is not closed; it is open. They can leave whenever they want”.

Russia’s leverage is waning in both countries.

In Azerbaijan, the Ukraine invasion turned public opinion further against Russia and its peacekeeping contingent, said Zaur Shiriyev, a Crisis Group analyst in Baku.

In Armenia, Russia’s military support looks less advantageous, with Russia no longer a prolific exporter of weaponry – it needs it in Ukraine – and with Putin keen to preserve close ties with Turkey, Azerbaijan’s main ally.

Tigran Grigoryan, an Armenian political analyst, said the war in Ukraine had “created an environment in which the Russian deterrent isn’t working in the region”.

There is little clarity on how the current crisis can be resolved.

Azerbaijan insists that it has not imposed a blockade on Nagorno-Karabakh and that humanitarian and medical traffic is being let through.

But on the ground, the situation appears increasingly dire for Armenians in Nagorno-Karabakh who are stranded with limited food and other essentials, and cut off from family members who were in Armenia when the crisis began.

Although Azerbaijan won the 2020 war, it still has not achieved all its aims, including a transportation corridor to the Azerbaijani exclave of Nakhchivan – a separate slice of Azerbaijani territory on Armenia’s south-western border – that would give the country a direct link to Turkey.

It is also seeking to exert greater control over the road that is now being blocked, known as the Lachin Corridor, claiming that Armenia is using it to illegally transport land mines into the territory.

The Kremlin continues to keep a hand in the talks between Azerbaijan and Armenia, and Mr Putin spoke with Aliyev and Armenian Prime Minister Nikol Pashinyan last month in St. Petersburg.

In televised remarks at his meeting with Mr Putin, Mr Pashinyan noted with apparent frustration, “It turns out that the Lachin Corridor is not under the control of Russian peacekeepers.”

With Moscow distracted, the European Union and the United States have heightened their own efforts to broker a lasting peace and to build their influence in the Caucasus.

Mr Pashinyan and Mr Aliyev met in August and in October in meetings arranged by the EU, and the two countries’ foreign ministers met in Washington in November.

Analysts described the dual negotiating tracks as unusual – one led by Russia, the other by the EU – at a time when Moscow and the West are locked in their most intense conflict in decades.

But the EU’s special representative for the southern Caucasus, Toivo Klaar, said in an interview that he had been in contact with his Russian counterpart, diplomat Igor Khovayev, and met in person with him twice last autumn.

“In the current circumstances there’s potentially more space for Armenia and Azerbaijan to actually overcome their conflict,” Klaar said. “The question is whether they’re able to seize that opportunity.” NYTIMES