Leading up to, or sometime during the Korean War conflict, the US decided due to political and strategic reasons that they would not use nuclear weapons against North Korea - even as there was great concern that the North Koreans would push the US off the Korean peninsula. Moving the clock forward over 50 years, President Bush in Dec 02 directed that the US would "field missile defense capabilities to protect the United States..." The Missile Defense Agency is currently spending close to $10B a year to field and refine a system that will defeat ballistic missile launches from North Korea. If North Korea chooses to launch a nuclear-tipped ballistic missile that our defensive systems engage and defeat, would we respond in kind? Or are the strategic and political factors that fed into the decision during the first Korean conflict the same today - thereby possibly negating the threat of US nuclear retaliation?