For the last few years, Iran has been openly flirting with the idea of developing nuclear weapons, but a show-down has been staged for August this year.
The stakes are high: European governments are concerned that Iran's nuclear programme could set off spiral of proliferation in the Middle East (with Saudi Arabia, Turkey and even Egypt looking to acquire nuclear weapons). They also believe that a nuclear Iran could kill off the Non-Proliferation Treaty which has already been undermined by the nuclear programmes of India, Pakistan and Israel, and North Korea's decision to abandon the treaty in 2003.