Key point: The seas will soon be ruled by drones.
Imagine a future in which nuclear attack submarines (SSNs) can deploy undersea drones (UUVs) to hunt, and possibly kill, enemy subs. The U.S. Navy, at least, is taking steps to make this a reality. What impact could this have? On the one hand, UUVs could shake modern antisubmarine warfare (ASW) to its core, making existing platforms vulnerable or obsolete. On the other hand, the development of UUVs could reinforce existing hierarchies; in contrast to popular understanding, established organizations are often the best at adapting to disruptive military innovations. The future of the U.S. Navy depends to great extent of which of these becomes a reality.
In a sense, submarine launched drones have existed for quite some time; even in World War II, navies used pattern following or acoustic homing in order to find their targets. Wire guided torpedoes were introduced in the 1960s, allowing the submarine a measure of control over how the weapon approached its target. These torpedoes are suicidal drones in the same sense as cruise missiles; weapons that can be launched, then directed to their target either through autonomous mechanisms or by user interface.
Both the United States and competitor nations have eagerly pursued the potential of UUVs. UUVs can contribute to both the hunting and the killing parts of ASW, although as of yet the only firm plans involve using them in the former. Such drones offer better opportunities to track and destroy diesel-electric subs, even those which use Air-independent propulsion (AIP) technology. These vessels can operate more quietly than manned subs, and remain submerged for a greater length of time. Instead of hunting enemy submarines, they can simply lay in wait until the prey comes to them.