Mohsen Fakhrizadeh may be the most senior Iranian nuclear scientist to have been assassinated but he is certainly not the first, joining at least four others during the past decade.
In killings Iran said were aimed at sabotaging its nuclear energy ambitions – it does not acknowledge using the technology for weapons – the country has consistently pointed the finger at Israel, its regional arch-foe.
Israel maintains a policy of not commenting on such allegations. Meanwhile, the US, which Iran accuses of complicity, has denied accusations.
However, Israel has long cited its enemy’s pledges to destroy it. It says, often without specifics, that it has the right to defend itself by blocking Iran from becoming a military nuclear power. The country’s foreign intelligence agency, Mossad, has a record of using targeted assassinations.
Iranian scientist killings appear to have followed a pattern, often taking place as the men were on their way to or from work.
In 2010, Masoud Ali Mohammadi, an expert on particle physics, was killed by a remote-control bomb strapped to a motorcycle as he was leaving his Tehran home.
Later that year, another nuclear scientist, Majid Shahriar, died in similar manner when attackers rode up alongside him and stuck bombs to his car. Fereidoon Abbasi Davani, Iran’s atomic chief at the time, survived an assassination attempt that same day. Both men are believed to have worked with Fakhrizadeh.
In 2011, Darioush Rezaeinejad, an academic whose affiliation to the country’s nuclear activities is disputed, was shot by gunmen riding on motorcycles. A year later, Mostafa Ahmadi Roshan, the deputy head of Iran’s uranium enrichment facility at Natanz, was killed in a magnetic bomb attack while he was driving his Peugeot 405 to work.
The timing of the killing of Fakhrizadeh on Friday, so many years after the spate of assassinations early last decade, remains unclear. What is certain, however, is that the region is on edge as the Trump administration enters its final weeks.
The US president has been extremely hawkish on Iran, including ordering a drone strike this year that killed its most powerful general, Qassem Suleimani. In general, Donald Trump is seen in Israel as more permissive of its ambitions, both political and military, than Joe Biden. That puts pressure on the country to move ahead with any plans before the January transition.
Israel has acknowledged pursuing covert operations against Iran’s nuclear programme to gather intelligence. In 2018, the prime minister, Benjamin Netanyahu, said his government had acquired tens of thousands of documents from what he called Iran’s “Atomic Archives”.
The speech was largely seen as a televised show specifically for Trump – it was aired just two weeks before the US president was due to decide whether to pull out of an Obama-era deal that waived US sanctions on Iran in return for it scaling down its nuclear activities.
Netanyahu had been vehemently against the deal and accused Tehran, which he labels a “terrorist regime”, of developing nuclear arms.
In that presentation, Netanyahu referred to Fakhrizadeh multiple times as the director of Iran’s nuclear weapons project. “Remember that name, Fakhrizadeh,” he said.
Even without confirmation of who did it, Fakhrizadeh’s death will inflame an Iranian-Israeli conflict that has increasingly erupted into the open.
In its war-torn neighbour, Syria, Israel has carried out hundreds of cross-border strikes against Iran’s proxies, including the Lebanese militant group Hezbollah, but also in recent years directly against Iranian forces.
There have been dangerous confrontations closer to home too. In February 2018, the country said it downed an Iranian stealth drone entering Israeli-controlled airspace, which Israel later said was armed with explosives.
Later that year, Israel accused Iran of firing a barrage of rockets from Syrian territory at its forces in the occupied Golan Heights. It was the first time Iran had fired rockets in a direct strike on Israeli forces, dramatically ratcheting up the conflict.