The strategic strength of the submarine fleet depends on its ability to move around the globe undetected. Even in peacetime, submarines represent the front line of deterrence. It is the fact that submarines can be just about anywhere, anytime that keeps those who would wish us harm from attempting anything stupid.
An active sonar ping can be heard sometimes for hundreds of miles under water, depending on conditions. Even a single ping is like throwing up a beacon that says, "Here I am!"
Hope that explanation helps.
Yes, it helps a lot. Thanks.