UNITED NATIONS: Intelligence agencies estimate that it would probably take Iran a minimum of 18 months to develop a nuclear weapon if it chose to build one, Western diplomats and intelligence officials said.

For years the US Central Intelligence Agency, Britain's MI6, Israel's Mossad, their French and German counterparts and other spy agencies have been struggling to penetrate Iran's secretive nuclear program, often disagreeing internally and with each other on when Iran could have a nuclear weapon.

Teheran insists that its nuclear program is peaceful and says Western spies are lying when they suggest Iran is pursuing nuclear weapons. Some officials at the UN nuclear watchdog in Vienna have warned against exaggerating the case against Iran, as happened with prewar Iraq.