Final answer:
The sole mission and fundamental reason for the existence of fleet ballistic missile submarines is deterrence through nuclear missile capabilities. These submarines are designed to carry and launch nuclear missiles from beneath the surface of the ocean, providing a strong deterrent against potential adversaries.
Step-by-step explanation:
The sole mission and fundamental reason for the existence of the fleet ballistic missile submarine in the field of naval operations or strategic submarine forces is deterrence through nuclear missile capabilities (C).
The fleet ballistic missile submarine is designed to carry and launch nuclear missiles from beneath the surface of the ocean. This capability ensures that they can operate covertly and remain undetected by enemy forces, providing a strong deterrent against potential adversaries. By maintaining a credible nuclear threat, these submarines contribute to the principle of mutually assured destruction, preventing any nuclear attack.
For example, during the Cold War, both the United States and the Soviet Union deployed fleets of submarines armed with nuclear missiles. These submarines patrolled the oceans and provided a constant deterrent against a first strike from the other side. The submarines' ability to remain hidden and their strategic positioning made them a vital component of the nuclear deterrence strategy.