With new presidents and a changed Middle East, what are the chances of a US-Iran reset?

US president-elect Donald Trump is inheriting a golden opportunity from President Joe Biden to finally prove to be the great international "dealmaker” of his ambitions. Mr Trump will enter office facing a profoundly weakened Iran that was already suing for talks with Washington a year ago and is now perfectly positioned to have to accept a deal that is highly advantageous for the Americans. The stars are so perfectly aligned that it would take considerable clumsiness for anyone to fail.

Mr Trump always measures his successes against those of his predecessor, Barack Obama. His entire political career was based on insisting that Mr Obama was born in Kenya and therefore was ineligible to be president. It was a huge lie, but it catapulted him to national prominence.

As president, Mr Trump set to work destroying as much of Mr Obama's legacy as possible. He just barely failed to eliminate "Obamacare" – although now he claims to have "saved it" – blocked at the last minute by the late Arizona Republican Senator John McCain. But nothing could prevent him from ripping up Mr Obama's signature foreign policy achievement, the nuclear agreement with Iran.

Mr Trump then exerted a two-year campaign of "maximum pressure" sanctions against Iran, but his administration never reached an internal consensus about whether the purpose of this pressure was softening up Tehran for a new and better deal than Mr Obama’s, or the dream of a change of government in Iran (which would unlikely be caused by external forces). The policy, therefore, drifted pointlessly.

Now, however, Mr Trump will find Iran profoundly diminished and probably desperate to make a deal. He is unlikely to give any credit to Mr Biden, but it is during the past 14 months that Tehran's national security strategy has fallen to pieces in the aftermath of the October 7, 2023 Hamas attack on southern Israel. This has been partly because of Israel's actions in Gaza and Lebanon, extreme miscalculations by Hezbollah and Iran itself and, worst of all, the indirect consequence of the downfall of the Assad government in Syria.

Iran's "axis of resistance" barely exists anymore. Only the Houthis in Yemen pose any kind of serious military threat to anyone at all. The Iranian national security strategy in recent decades centred on a forward defence against Israel and the US conducted through client militias, led by Hezbollah and eventually including groups such as pro-Iranian Iraqi and Afghan militias and Pakistani mercenaries in Syria, as well as, of course, the Houthis in Yemen.

Hamas was not a core member of this alliance, but a Muslim Brotherhood organisation in an uneasy alliance of convenience with Tehran and its "axis". Iran and its network were relatively unaffected by anything that has happened in Gaza since the October 7 attack. But once Israel concluded the main part of its war against Hamas, it turned its attention to Hezbollah.

That organisation, the key to Iran's regional network, saw no reason to go to war with Israel over Hamas, but nonetheless felt the need to maintain its "revolutionary" and "resistance" credentials, so it attempted to square the circle by having a limited confrontation, but not an all-out war, with the Israelis. For many months, they refused to stop firing rockets at Israel as long as the Gaza war continued. Israel called their foolhardy bluff, and virtually wiped out the organisation.

Rebel groups in northwestern Syria saw the opportunity, and with Turkish support attacked Aleppo. When that city fell in just over a day, it became clear the Assad government was totally hollowed out and would not be saved by the coalition of Russia, Iran and Hezbollah that came to its rescue in 2015. The rebels won.

Suddenly Iran was without its principal militia and only major state ally. Forward defence and the "axis" were exposed as useless.

One potential answer is to sprint towards a nuclear bomb. But the Iranians know that the US has a plan in place, which would probably take rather less than a week, of round-the-clock bombings with bunker buster bombs delivered by B-2s that would destroy the entire nuclear infrastructure once the US gets wind that Iran is moving in that direction.

Iran still has one major card to play: the dramatic enrichment and R&D improvements it has made since Mr Trump withdrew from the nuclear deal. This week the rial has once again fallen to a new low. Iran desperately needs sanctions relief.

It could make a similar deal with Mr Trump as it did with Mr Obama, freezing further nuclear progress and putting crucial parts of its enriched uranium stockpile in a kind of escrow, held perhaps by India (instead of Russia), while scrapping many highly sophisticated centrifuges. The engineering knowledge, after all, will remain.

The US will undoubtedly try to once again place Iran's militia clients and missile arsenal on the table, though Iran rejected that in 2015 and 2016. This time, given the failure of forward defence, why not agree to limit support for groups such as Hezbollah and even the Houthis? Iran won't give up on Hezbollah completely. It's a 40-year old project. But it might agree to parlay some of that support into further sanctions relief, allowing Mr Trump to declare that he had got a much better deal out of Iran (without crediting Mr Biden).

Tehran will no doubt keep missiles off the table, since unilateral disarmament is highly unusual and the country will feel it's their last line of defence. But a reasonable agreement on its nuclear programme and a deal to seriously pull back from weapons supplies and similar illicit support to militia groups in the region could give Mr Trump a stunning, albeit not that difficult, diplomatic coup.

Iran really doesn't have much of an alternative. If it sprints for a bomb, the US will obliterate its facilities in a few days. Tehran is well aware that Washington has the plan and the equipment at the ready and it's simply a matter of giving the order. So, there isn't much point in such a sprint towards disaster. Much better to buy time, relative safety and breathing space by making a deal with Mr Trump as soon as possible.

Without him lifting a finger, his long-promised "better deal" with Iran is waiting for him on a silver platter, right next to his beloved Diet Cokes.