Saudi Arabia has made a secret deal with Pakistan to purchase nuclear weapons in case Iran acquires nukes. Nukes in the hands of Wahhabists, that's just what the world needs! Continued nuclear proliferation presents a clear and present danger to the United States and dramatically increases the risk of a nuclear attack on the us. Consider this scenario:

September 11, 2009: A container ship enters the harbor of Los Angeles and a nuclear weapon detonates. There are over 1 million casualties. The US investigates the source of the attack, but can only trace back the ship to Singapore, where it took on containers from a variety of nations that could be a source of it. It could have been Iran, long time sponsor of terrorism. Saudi Arabia, homeland of Wahabbi extremism. Or Pakistan, where the Taliban still enjoy many friends. It could also be a nuclear weapon sold by North Korea or a warhead that was stolen from Russia. All possible countries of course deny that the weapon originated from their country. The US cannot strike back because there is no target. All we can do is hope that the next nuke does not get through by closing our borders, collapsing global trade and bring on another great depression. Unlikely? Impossible? How many lives are you willing to bet on that? Would it be easier and cheaper to take out those governments today, than to wait for a far more threatening situation to arise? Undoubtedly. If we fail to act today, future generations might curse us for allowing the world to come to the brink of destruction. However, if we act today, we will be accused of acting unilaterally, without proper casus belli, just as we were accused during Operation Iraqi Freedom.