Paris (AFP) - Waging brutal repression at home and allegedly helping Russia in its war against Ukraine, Iran is becoming an unsolvable challenge for Western powers eager to avoid a new nuclear power in the Middle East.
"We're in a delicate situation and an obvious impasse," a French diplomat admitted before Wednesday's UN Security Council meeting on suspected Iranian drone use by Russian forces.
Despite Tehran's new support for an increasingly isolated Moscow, the United States and the European Union still hope to revive the 2015 deal aimed at curtailing Iran's nuclear programme -- even though the prospect is dimming.
"Iran's repression at home and aggression in Ukraine have increased the political cost for and decreased the appetite of the West to grant Tehran sanctions relief," said analyst Ali Vaez of the International Crisis Group.
"But the West has no good options, as the only thing worse than a repressive regime that kills its own people is a nuclear armed one that does so."
Iran has denied supplying Russia with cheap kamikaze drones that have targeted Ukraine for weeks, though European and American officials say they have clear evidence, and on Thursday the European Union slapped new sanctions on the Islamic republic.
Experts say the West is walking a fine line, recognising the need to punish Tehran but not wanting to escalate tensions to a breaking point.
"The Iranian government denies the arms shipments to limit the damage with the West," said Clement Therme, of the Paris-based Iranian Studies Institute.
But he said officials have tacitly confirmed the shipments, noting comments by supreme leader Ayatollah Ali Khamenei on Thursday mocking those who doubted the existence of Iranian drones just a few years ago.
'New world order'
The 2015 agreement, known formally as the Joint Comprehensive Plan of Action (JCPOA), gave Iran sanctions relief in return for restricting its nuclear programme.
It has been in tatters since then-president Donald Trump withdrew the United States from it in 2018, but on-off talks have taken place since 2021 in a bid to revive it.
Iran's crackdown on the most intense anti-government protests in years, sparked by the death of 22-year-old Mahsa Amini in police custody last month, further limits the West's options.
"The bloody repression and the rapprochement between Tehran and Moscow pose a serious problem for the West," stifling any hope of a new nuclear deal, said Farid Vahid of the Jean-Jaures Foundation, a French think-tank.
"Today it's completely unimaginable to see an American official and an Iranian official sign an agreement."
Despite decades of mutual distrust between Russia and Iran, both countries now see common interests in resisting Western powers and their crippling sanctions.
"The Islamic republic is betting on a new world order and the end of Western dominance," Vahid said.
"It's very ideological and does not at all match the aspirations of Iranian society, but it's the reality."
Vaez agreed that the Iran-Russia axis "has morphed from a tactical partnership into a strategic relationship."
Tehran fears "Russia's weakening in Ukraine will deprive Iran of the only great power it can rely on," he said, and wouldn't let that happen "at any cost".
'No plan B'
Iran, also accused of planning to provide Russia with surface-to-surface missiles, could also see it as a chance to modernise its own military.
Several experts say Iran is hoping to receive Russian Sukhoi SU-35 combat jets and S-400 anti-missile systems, which could increase its prospects of intervening in conflicts across the Middle East.
Washington and the EU consider Iran's weapons shipment to Russia a violation of the UN resolution endorsing the 2015 nuclear deal, but have no appetite to push Tehran farther away from the negotiating table.
"Iran has really become a pariah, and the Russians, who have access to its top leadership, are no longer interested in helping the Americans bring back" the nuclear accord, Therme said.
"Diplomacy is destined to fail."
But for Vahid, that's a position Western nations are unable to take.
"If we accept the JCPOA is dead, what do we do?" he said.
"Nobody has a plan B, and nobody wants to embark on a new military adventure in the Middle East."
