I believe the "subs as aircraft carriers" idea came from the fact that you generally want to interact with a target location on land. Nation states don't tend t

I believe the "subs as aircraft carriers" idea came from the fact that you generally want to interact with a target location on land. Nation states don't tend to have too many strategic targets underwater off their coasts. Options for interacting with a target land location (dates extremely rough, in rough historical order): - Subsonic aircraft: outpaced by projectile-based anti-aircraft since ~1935 - Supersonic aircraft: outpaced and obsoleted by missile and satellite technology since ~1970 - Satellite: excellent for reconnaissance and elint, limited interactive capabilities due to treaty obligations - Subsonic cruise missiles (aka light missiles): limited range (relative to coastal approach), limited survivability against active anti-aircraft defenses - ICBM (aka heavy missiles): expensive, high risk of escalation due to detection, risk of nuclear payload, and ability to apply last minute target corrections - Carrier launched aircraft: limited range, limited survivability against active anti-aircraft defenses - Supersonic cruise missiles: limited range, limited survivability against active anti-aircraft defenses - Drones: limited range, limited survivability against active anti-aircraft defenses You ideally want an aerial platform (freedom of movement, ability to interact with land targets), survivable in a hostile environment, as cheaply as possible. This was solved by a carrier air wing. However, the idea of A2/AD is to push the survivability line out far enough that the carrier can no longer approach close enough to let its air wing operate efficiently. The obvious go to is to take a platform that can penetrate that A2/AD coverage to a greater depth with acceptable survivability. (It's a lot easier to hide a submarine than an aircraft carrier / it's a lot more expensive to build a submarine detection net across large ocean regions) Then have that platform launch the equivalent of an air wing. E.g. stealth submarines serving as carriers for limited-range (because that buys you design to make them stealthier / more survivable / faster) aerial drones