February, 2009: IAEA Director-General Mohamed ElBaradei said Iran was not allowing UN inspectors to determine if it was working developing nuclear weapons.
June, 2009: IAEA reveals it was blocked from inspecting nuclear facilities, but Mr ElBaradei voices opposition to Israel support for military strike, saying it would turn region into 'ball of fire'.
July, 2009: Israeli Prime Minister Benjamin Netanyahu said he had agreed with President Barack Obama to engage with Iran until the end of the year, but the country would be free to take on the 'existential threat' with military force after the deadline passed. Mr Obama also gave Iran until September to adhere to IAEA proposals or 'face consequences'. Iran threatens to strike back at Israel if its nuclear facilities were targeted.
September, 2009: Second enrichment facility is revealed 20 miles north of Qom, Iran.
January, 2010: Masoul Ali Mohammadi - a particle physicist - is killed by a remote-control bomb as he left for work.
August, 2010: Iran acquires nuclear fuel rods from Russia and begins fuelling of Bushehr I reactor - reportedly to generate electricity.
October, 2010: Stuxnet computer worm infects systems at Natanz enrichment plant, causing centrifuges to crash and suspending work.
November, 2010: Second physicist, Majid Shahriar, killed when bomb was stuck to the side of his car by a motorcyclist.
July, 2011: Darioush Rezaie - third physicist involved in Iran's nuclear programme - shot dead.
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Iran attack 'drawn up by UK and US' as Middle East tensions rise | Mail Online