It all tends to add up to a very major military effort -- not the simple "one and done" raid Israel carried out on Iraq's Osirak nuclear reactor in 1981.

CNN: Questions fly around any plan to attack Iran

In 1981 it bombed Saddam Hussein's Osirak reactor, and in 2007 it bombed a suspected Syrian nuclear reactor under construction.

ECONOMIST: Nuclear proliferation

In nineteen eighty-one, Iraq was on the point of acquiring nuclear power. 10.17.01 Narrator The Osirak reactor was an experimental plutonium plant.

BBC