Human: What is the name of the Soviet system that ensured that nuclear retaliation, and hence deterrence, remained possible even if its leadership were to be destroyed in a surprise attack? Assistant: 
The Soviet Union took steps 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