Plans that President-elect Joe Biden might have had to restore ties with Iran to levels that had existed during Barack Obama’s presidency have received a severe setback with the assassination of a top Iranian nuclear scientist on the outskirts of Teheran at the weekend.

Teheran has accused Israel and the United States of orchestrating the killing of Mohsen Fakrizadeh who had been named two years ago by Prime Minister Benjamin Netanyahu as the scientist heading Iran’s efforts to build nuclear weapons. The assassination appears to be an effort to weaken Iran’s nuclear programme in the last days of the Trump presidency and if carried out by Israel could not have taken place without Washington’s blessings.

But it is certain the development will affect the fragile peace in West Asia at a time many had hoped that a Democratic administration in Washington would seek to pick up the threads of the Joint Comprehensive Plan of Action initiated by Mr Obama in 2015 that was rescinded by his successor.

The Iran nuclear deal, as it is called, had involved, besides the United States and Iran, the United Kingdom, France, China and Russia, and was considered the signal foreign policy achievement of the Obama administration, It had involved a commitment by Teheran to limit sensitive nuclear activities and opening itself up to international inspections in return for a lifting of economic sanctions.

The deal was abandoned by President Trump in 2018 who termed it “defective at its core” and re-imposed sanctions. Earlier this month, the International Atomic Energy Agency in a report claimed that Iran’s stockpile of low-enriched uranium was now twelve times the limit set by the abrogated deal and was theoretically enough to produce two nuclear weapons.

Immediately thereafter, President Trump was reported to have consulted top security advisers on the feasibility of attacking Iran’s main nuclear site. But he was reportedly advised not to do so as such an act would provoke a wider conflict.

The assassination of Mr Fakrizadeh must be viewed against both this backdrop and a statement by Mr Biden that he could consider re-joining the deal if Teheran agrees to go back to full compliance and makes itself open to further negotiations.

While Iran’s leadership sees little chance of a significant change in US policy despite Mr. Biden’s victory, and this may in part be because of the restructuring of West Asian geopolitics in the last year of the Trump presidency, even lingering hopes are likely to be dashed by the assassination of the top scientist. Washington and Teheran had come close to a conflict after an Iranian general, Qassem Solemaini, was killed in a targeted drone attack sanctioned by President Trump last January.

This had led Iran to fire missiles at bases housing American troops in Iraq, which caused several injuries. Thereafter, the coronavirus epidemic which had flared up early in Iran, put offensive actions on hold. The imminent changes in the top at Washington appear to have re-ignited tensions.