A report published by Reuters said that the killing of Iranian nuclear scientist Mohsen Fakhrizadeh in an ambush near Tehran on Friday could trigger a confrontation between Iran and its opponents in the final weeks of Donald Trump's presidency of the United States.

The report added that the assassination of the scientist whom the West had long suspected of being the mastermind of a secret nuclear bomb program would complicate any effort by US President-elect Joe Biden to revive the accord that existed between Tehran and Washington during Barack Obama's presidency.

The agency also referred to Iran’s accusation against Israel of being responsible for the attack, with the implication that US President Trump "blessed the killing."

Iranian Foreign Minister Mohammad Javad Zarif said on Twitter that there are "dangerous indications of an Israeli role," and called on Western countries to "end their shameful double standards and condemn this act, which is state terrorism."

Hossein Dehghan, the military advisor to the Iranian guide, was more clear in accusing Tel Aviv and referring to Trump, as he said in a tweet on Twitter, "In the last days of the political life of their ally (Trump) the Zionists seek to intensify pressure on Iran and ignite an all-out war."

As for Sheikh Naim Qassem, Deputy Secretary General of the Lebanese Hezbollah, he said that Fakhri Zadeh was killed "by those sponsored by America and Israel, and this is part of the war on Iran, the free zone and Palestine."

The complexity of Biden's mission

Robert Malley, who worked as an advisor to Obama on the Iranian file and informally advises the Biden team, said that the killing of Fakhrizadeh comes within the framework of a series of moves that took place during the final weeks of Trump's term, and aims to make Biden's mission difficult to reconnect with Iran.

"One of the goals is simply to inflict the greatest possible damage on Iran economically and its nuclear program ... and the other goal is to complicate Biden's mission related to the resumption of diplomatic efforts and the return to the nuclear agreement," he said in statements to Reuters, noting that he did not mean by that to launch speculation about who was responsible for the assassination on Friday.

For his part, US Senator Chris Murphy, the most senior Democrat on the Middle East Subcommittee in the US Senate, said on Twitter, "This assassination does not make America, Israel, or the world safer."

Before news of the attack on Fakhrizadeh came out on Friday, an Israeli official said that Israel was discussing with Gulf Arab states how to deal with Iran.

"The story is not Trump, not even Israel. The story is Iran ... the growing fear of a new US administration returning to the nuclear deal that threatens the existence of the Gulf states," Tzachi Hanegbi, a member of the security cabinet, told Radio 102 in Tel Aviv.

Escalation and intimidation

Channels on the encrypted messaging app Telegram believed to be close to the Iranian Revolutionary Guards reported that the highest security body, the Supreme Council for National Security, held an emergency meeting with senior military commanders.

The commander of the Iranian Revolutionary Guard, Major General Hossein Salami, said that Tehran had taken "a decision to take revenge and harsh punishment against those who planned, carried out and supported the assassination of Mohsen Fakhrizadeh."

On the other hand, capitals fell silent, as Israel refused to comment, and in the United States the White House, the Pentagon, the State Department and the CIA refused to comment, and Biden's transition team declined to comment.

For his part, Michael Mulroy, a former senior US Defense Department official in the Trump administration, said that Fakhrizadeh was the most senior Iranian nuclear scientist, and that killing him would be considered a setback that impedes Tehran's nuclear program.

He added that the alert levels in countries where Iran could implement a retaliatory response should be raised immediately.

Intelligence services in Israel and Western countries have long described Fakhrizadeh as the leader of a secret atomic bomb program that was stopped in 2003, and Israel and the United States accuse Tehran of trying to restart it in secret, and Iran has long denied that it is seeking to produce nuclear weapons.

Trump has repeatedly accused Iran of secretly seeking to acquire nuclear weapons, and decided to withdraw the United States from the nuclear agreement under which sanctions were lifted against Iran in exchange for restrictions on its nuclear program, while President-elect Joe Biden said that he would rejoin the agreement, although analysts say that this will not happen overnight. Overnight, and both sides will ask for guarantees.

Fakhrizadeh, a central figure in a presentation by Israeli Prime Minister Benjamin Netanyahu in 2018 (Reuters)

"Remember this name well."

Fakhrizadeh, who has not made a public appearance, is believed to have presided over what the International Atomic Energy Agency and US intelligence services believe to be a coordinated nuclear weapons program in Iran, but the program was suspended in 2003.

Fakhrizadeh was the only Iranian scientist named in the IAEA's 2015 "final evaluation" of open questions about Iran's nuclear program, and the agency's report said he had overseen activities "in support of a possible military dimension to Iran's nuclear program."

Fakhrizadeh was a central figure in a presentation by Israeli Prime Minister Benjamin Netanyahu in 2018, accusing Iran of continuing to pursue nuclear weapons, and Netanyahu said at the time, "Remember this name ... Fakhri Zadeh" showing a rare photo of him.

A US official confirmed earlier this month that Trump had sought to obtain a plan from military aides to strike a potential strike against Iran, but reversed that decision at the time due to the risk of a wider conflict in the Middle East.