A deterrent is "used" just by being deployed. The point of deterrence is to demonstrate that you have the capability, not necessarily putting it to use in comba

A deterrent is "used" just by being deployed. The point of deterrence is to demonstrate that you have the capability, not necessarily putting it to use in combat. Deterrence is a peacetime activity intended to preserve and extend peacetime as long as possible. One could argue that the fact that no two major powers have engaged in direct combat since ww2 is an existence proof of the power of deterrence.