When the same calculations were run for Nike-X, it was calculated that they would have to deploy 7,000 Sprint missiles, and the cost-exchange ratio was 20-to-1 in favor of the Soviets. When presented with these numbers, McNamara concluded that deploying Nike-X would prompt to Soviets to build more ICBMs, increasing the risk of an accidental war. From this point on, he opposed building a "heavy" ABM system like Nike-X.
