Transparent Oceans: The Defeat of the Soviet Submarine Force

The Soviet submarine force threatened the United States from the early 1960s until the end of the Cold War. The destruction of the Soviet missile submarines was the responsibility of the United States Navy; it remained their number one priority throughout the Cold War.
The apparently insoluble problem of destroying the Soviet submarines was actually solved by an unknown program called the Long Range Acoustic Propagation Project (LRAPP). The efforts of LRAPP made the oceans transparent; the Soviet submarine force could essentially be destroyed, on command, starting in the late 1970s. The total cost for this unheralded and virtually unknown organization was less than $250M over a 25 year period.
The solution to the antisubmarine warfare problem was a major part of the success of the West in winning the Cold War.