Dead Hand

A weapons system, implemented by the Soviet Union and by the Russian Federation as the successor state thereof, capable of closing a strategic nuclear strike control loop in the absence of normal command and control channels, analogous in concept to a dead man's switch, in anticipation of a decapitation strike.

Near-synonyms: doomsday weapon, doomsday device, doomsday bomb

Sometimes people glibly speak as if the Dead Hand were a thing of the past, but it is foolhardy to assume so.

Any such system, whether the cardinal instance (the Soviet/Russian one) or another.

The talk then turned darkly to the prospects for building a Dead Hand of their own.