The clock is ticking on Iran's race to go nuclear and diplomatic efforts to stop it are on their last legs.
Iran's Nuclear Secrets
Tuesday, 3 May, 2005
2100 BST on BBC Two
For nearly two decades, key nuclear facilities in Iran have been kept secret.
The Islamic state says it has been developing nuclear energy for purely peaceful purposes.
But the US believes Iran has been developing weapons of mass destruction and wants to send it to the UN Security Council.
Does Iran have a secret nuclear bomb programme?
Even if it has, what can the world do about it?
The This World team gain exclusive behind-the-scenes access to the UN's nuclear watchdog in Vienna, the International Atomic Energy Agency (IAEA), as they scrutinise Iran's nuclear capability.
We travel to Iran with the agency's weapons inspectors and meet the Iranian negotiators who remain adamant they have nothing to hide.
We also speak exclusively to Mohamed ElBaradei, Director General of the IAEA, the man caught in the diplomatic crossfire between states eager to join the nuclear club, and those already in who do not trust the outsiders to play safe.
Will Iran be able to convince the weapons inspectors it can be trusted?
"I keep saying to the Iranians," Mr ElBaradei tells us, "the more transparent you are, the better for you because we will never be able to establish confidence... unless we see full openness."
If Iran refuse to suspend their nuclear energy programme, the diplomats may have to make way for military strategists.
Is the club about to gain a new member? Or will the US lose patience with the flagging diplomatic effort?
Iran's Nuclear Secrets was broadcast on Tuesday, 3 May, 2005 at 2100 BST on BBC Two.
Producer/director: Paul Kenyon
Executive producer: Karen O'Connor