( CNN ) -- Former U.S. President Bill Clinton said Tuesday he does not trust Tehran 's assertions that it is not pursuing a nuclear weapon , and he urged the international community to pressure Iran 's President Mahmoud Ahmadinejad to allow inspectors to verify his claims . `` What they 're really saying is , in spite of the fact that we deny the Holocaust , that we threaten Israel , and we demonize the United States , and we do all this stuff , we want you to trust us , '' Clinton told CNN 's Piers Morgan in an interview to air Tuesday night . `` They do n't have a tenable position . '' If Tehran were to obtain a nuclear weapon , `` the retaliation would be incomprehensible , '' and others in the region would attempt to join the elite club of nuclear powers , Clinton said . Facebook : How should we respond to Iran ? As the number of such weapons grows , the more likely they may be stolen or transferred to terrorists , he said . `` Even if the government did n't directly sanction it , it would not be that much trouble to get a Girl Scout cookie 's worth of fissile material which , if put in the same fertilizer bomb Timothy McVeigh used in Oklahoma City , is enough to take out 20 % to 25 % of Washington D.C. -- Just that little bit . '' In 1996 McVeigh detonated a truck in front of the Alfred P. Murrah Federal Building in Oklahoma City , killing 168 people . Ahmadinejad has said his country 's nuclear program is intended solely for peaceful purposes . Ahmadinejad UN address : Iran is under threat from West . Clinton said the current concern over possible weapons of mass destruction in Iran differs from the situation that occurred in Iraq in 2003 , when the United States led an attack on the government of Saddam Hussein after accusing him of harboring such weapons . None was found . In Iraq , `` there was never -- to me -- any credible nuclear intelligence , '' Clinton said . `` This is quite different . They do n't even pretend that they do n't have centrifuges '' of the sort needed to make weapons-grade material . Obama stresses diplomacy , humanity in speeches to U.N. , Clinton foundation . Ahmadinejad talks Israel , slams homosexuality on Piers Morgan Tonight . Watch Piers Morgan Tonight weeknights 9 p.m . ET . For the latest from Piers Morgan click here .
`` They do n't have a tenable position , '' Bill Clinton says of Tehran 's stance . If Tehran were to get a nuclear weapon , `` the retaliation would be incomprehensible , '' he says . Comment: