If U.S. national missile defense (NMD) were only about countering ballistic missiles deployed by rogue states, then whether to deploy limited NMD would be a “normal” national security issue. The military-technical question would concern feasibility: Would the missile defense work against the small missile forces that a few states may eventually deploy? The military-political questions would concern the risks to the United States of being vulnerable to rogue-state missiles and the amount Washington should be willing to pay for insurance against these risks. What makes NMD special is its unavoidable connection to U.S. strategic nuclear policy and to the United States’ political relationships with Russia and China.