These two glimpses of nuclear war primed Reagan for Able Archer 83, giving him a very specific picture of what would occur had the situation further developed. After receiving intelligence reports from sources including Gordievsky, it was clear that the Soviets were unnerved. While officials were concerned with the Soviet panic, they were hesitant about believing the proximity of a Soviet attack. Secretary of State George P. Shultz thought it "incredible, at least to us" that the Soviets would believe the US would launch a genuine attack. In general, Reagan did not share the secretary's belief that cooler heads would prevail, writing: