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What is the difference between the Dead Hand and Perimeter systems?
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The Dead Hand system was designed to ensure that nuclear retaliation, and hence deterrence, remained possible even if its leadership were to be destroyed in a surprise attack. In contrast, Thompson argues that Perimeter's function was to limit acts of misjudgment by political or military leadership in the tight decision-making window between SLBM/cruise missile launches and impact. He quotes Zheleznyakov on the purpose of Perimeter being "to cool down all these hotheads and extremists.