Submarines as an invasion-denial force

Can an extremely aggressive submarine build carry the campaign when invasions and convoy battles still require surface vessels?

Surface forces are still necessary, but enough submarines can deter invasion by making the expected losses to transports and escorts prohibitively high.

Surface forces remain necessary for invasion and convoy missions, but massed submarines can make an enemy landing prohibitively expensive. An opponent contemplating invasion must expect severe transport and escort losses before the surface battle is decided. This campaign choice applies historical sea-denial logic to the game's systems. The submarine fleet blocks enemy movement even though it cannot perform every naval mission itself.