What is the definition of strategic deterrence?

Answer 1

The military used to advance the concept that the possession of nuclear weapons would assure the owner nation freedom from attack.

The attack on the US Cole, and various attacks in Russia, Britain, and so on have shown that most of the time, a nuclear response would be overkill (no pun) and of negative effect.

In summary, Nuclear deterrence assures (assumes) that a nuclear response would be expected if a nuclear attack were made. War continues to be profitable.

Answer 2

Strategic deterrence is a national military strategy which is designed to deter, or discourage other nations from attacking. Nuclear weapons are stockpiled for this purpose. Nations do not want to ever have to use them, but by having them, they create a deterrence.