The Iranian government is attempting to salvage some influence with Syria’s new leaders, as Tehran reels from its sudden loss of authority in Damascus after the collapse of the regime of Bashar al-Assad.

The Iranian president, Masoud Pezeshkian, is already facing multiple domestic and international crises, including power cuts due to a lack of oil supplies, continued tensions over its nuclear programme and a row about a new law that will toughen punishments for women who do not wear the hijab. But it is the sudden loss of influence in Syria after the fall of Assad to rebel groups that is exercising Iranian officials most.

In the short term they want to salvage some influence with the rebels in Damascus. Iranian diplomats insist they were not wedded to Assad, and were disillusioned with his refusal to compromise. The foreign minister, Abbas Araghchi, said in an interview this week: “We had long ago reached the conclusion that the continuation of governance in Syria would face a fundamental challenge. Government officials were expected to show flexibility towards allowing the opposition to participate in power, but this did not happen.”

He added: “Tehran always had direct contacts with the Syrian opposition delegation. Since 2011, we have been suggesting to Syria the need to begin political talks with those opposition groups that were not affiliated with terrorism.”

At the same time, Iran’s foreign ministry spokesperson insisted it only entered Syria in 2012 at Assad’s request to help defeat Islamic State. “Our presence was advisory and we were never in Syria to defend a specific group or individual. What was important to us was helping to preserve the territorial integrity and stability of Syria.”

Such explanations have not cut much ice in Damascus. Iran remains one of the few countries criticised by Ahmed al-Sharaa, theHayat Tahrir al-Sham leader.

Many Iranian officials are claiming the current victory lap being enjoyed by Turkey in Syria may be brief as Ankara’s interests will start to diverge from the government led by HTS, a group that has its origins in al-Qaida and is designated as a terrorist group by Turkey.

The Grand Ayatollah Naser Makarem Shirazi said: “We must follow the Syrian issue with hope and know that this situation will not continue, because the current rulers of Syria will not remain united with each other”.

The conservative Javan newspaper predicted that “the current honeymoon period in Syria will end due to the diversity of groups, Salafism, economic problems, the lack of security and diversity of actors.”.

Officially Iran blames the US and Israel for Assad’s collapse, but resentment at Ankara’s role is rife, ironically echoing Donald Trump’s claim that Syria has been the victim of an unfriendly takeover by Turkey. In his speech responding to Assad’s downfall the supreme leader, Ayatollah Ali Khamenei, said a neighbouring state of Syria played a clear role” in shaping events and “continues to do so now”. The Fars news agency published a poster showing the HTS leader in league with Recep Tayyip Erdoğan, Benjamin Netanyahu and Joe Biden.

Iran’s Strategic Council on Foreign Relations questioned whether HTS would remain allies with Turkey for long. It said: “Although Turkey is only one of the main winners of Bashar al-Assad’s fall from power in the short term, Ankara can never bring a government aligned with itself to power in Syria. Even if Tahrir al-Sham attempts to form a stable government in Syria, which is impossible, in the medium term, it will become a major threat to Turkey, which shares an 830-kilometre border with Syria.”

The former Iranian president Hassan Rouhani predicted a bleak future for Syria and Turkey. “In recent weeks, all of Syria’s military power has been destroyed by Israel, and unfortunately, the militants and Turkey did not respond appropriately to Israel. It will take years to rebuild the Syrian army and armed forces.”

Mohsen Baharvand, a former Iranian ambassador to the UK, suggested the Damascus government may find itself overly reliant on Turkey. “If the central government of Syria tries to consolidate its authority and sovereignty through military intervention and assistance from foreign countries – including Turkey – Syria, or key parts of it, will be occupied by Turkey, and Turkey will enter a quagmire from which it will incur heavy human and economic costs.”

He predicted tensions between Turkey and HTS in particular about how to handle the Syrian Kurdish demand in north-east Syria for a form of autonomy. The Turkish-funded Syrian National Army is reportedly ready to mount an offensive against the Kurdish Syrian Democratic Forces in Kobani, a Kurdish-majority Syrian town on the northern border with Turkey.

Turkey’s foreign minister, Hakan Fidan, said on Wednesday that if the issue were addressed “properly” Ankara would not seek a military intervention. “There is a new administration in Damascus now. I think this is primarily their concern now,” Fidan said.

More broadly, the Syrian reverse is forcing Iran to accelerate a rethink of its foreign policy. The review centres on whether the weakening of its so-called axis of resistance – comprising allied groups in the region – requires Iran to become a nuclear weapon state, or instead strengthen Iran by building better relations in the region.

For years, Iran’s rulers have been saying that “defending Iran must begin from outside its borders.” This hugely costly strategy is largely obsolete, and how Iran explains its Syria reverse will be critical to deciding what replaces that strategy.