This is placing the political cart before the technical horse. If a missile defence system worked fully, it could spark a bigger arms race. If it did not work completely, then the possibility of mass destruction would linger. Bush argues that during the Cold War, the spectre of mutual destruction made it unlikely a Soviet leader would initiate a nuclear war but that today, with leaders like Iraq's Saddam Hussein, this is not so sure. Most Democrats at least support continued missile defence research and many support the deployment of boost-phase systems that could be aimed at small countries such as North Korea without unravelling the larger framework of deterrence that governs relations with Russia and China.
Critics also point to another issue.
To build political support for his missile defence plan, Bush has suggested that he will share this advanced technology with Japan, South Korea, Israel and Taiwan. In short, he proposes that the US become a significant proliferator of missile technology, despite having criticised other nations, including Russia and North Korea, for selling missile technology.