Sea-borne military forces are not obsolete. However, the types of the vessels themselves may be obsolete. Who would send a human-propelled trireme into action against the enemy today? And yet, at one time, the trireme was the very height of naval power projection.
In 1941 the world realised that the battleship was far outranged by aircraft, who were able to attack it long before the battleship was able to get close enough to the carrier to be able to use those 'powerful 16-inch guns'. At that moment, the battleship became obsolete. The biggest battleship ever, the 'Yamato', was no match whatsoever against carrier-borne aircraft.
The US still can't get into its head that the days of the carrier are gone now too. It will take an 'Arizona', 'Repulse' or 'Prince of Wales' kind of incident to change that policy. No need to spend 12 billion on a white elephant any more.
At the present time, lots of small ships with big missiles are the way to go. They pack as much punch as a super-carrier, but they are cheap and easily replaceable.
Why buy a 'Ford' when you could have a dozen or more equivalents for the same money?
> ...pouring vast sums of money into warships is essential to projecting power, preserving peace and so on (or, from a mirror image viewpoint, that the US Navy is central US global hegemony)
As long as the majority of potentially blockade-running trade is seaborne (air freight is expensive; railways are easy to target), I'd argue navies have a large role in "preserving peace", but obviously intra-eurasian trade would have different constraints to intercontinental.
EDIT: come to think of it, this would easily explain why russia is currently sitting in eastern ukraine: Novorossiysk (or Mariupol?) is much better placed than Murmansk.
No, obsolescence comes from having your role replaced by something else. Infantry should be obsoleted since WW1 thanks to invention of machine gun. But it is not, because there is nothing to replace its role on the battlefield.
Yet at the same way, you don't see horses on the front. Because they were replaced by combustion engine.
I suspect that navies are no longer viable as weapons platforms, but are still viable as force projections that can move across water.
Since we don’t yet have aircraft of comparable size and weapons/personnel capacity that can loiter and be on patrol without refuelling for days or weeks on end, we need to rely on navies to be the platforms our forces operate from. Their current design is a holdover and needs reworking to adapt to new combat environments, but I doubt we’ll see them vanishing any time soon due to a lack of adequately functional replacements.
Autonomous weapons systems will increase the usefulness of small ocean-going craft and things that hide on the sea floor, waiting for a chance to activate.
The world's navies got rid of armor and now they are vulnerable.
They got rid of armor because smart weapons could hit them anywhere, not just on a small armored belt just above the waterline. Armoring a ship's entire top and bottom (as well as sides) is heavy, and ships need to float.
If I were trying to establish a navy, I would concentrate on mass-produced, unmanned submarines or semi-submersibles that are hard to target without weapons that cost far more than they cost.
Water based drones instead of air. Would that make them more efficient, and able to travel further?
If not then it's pointless, but if so then I could see the nightmare scenario of a small submersible popping out near a port and a swarm of flying drones getting launched out of it.
But in a similar sense, massed firepower is also becoming obsolete. Ask Ukraine. A military version of flash mobs minimizes opportunities for detection and attack. (What is the naval version of flash mobs ? Iranian speedboats ?)
Pervasive airborne surveillance (visual but also EM) makes concentrations vulnerable - whether masses of troops, or large floating hulls.
This seems to favor the defense in all scenarios. Depending somewhat on your definition of "the defense".
the entire point of an SSBN fleet is that no one knows where they are
(consider the UK's "triad": they have no more air, no more land, and their seaborne missiles come from the US, but at least their boomers are from Cumbria, so they still have a permanent seat on the Security Council)
If you're curious as to how one might go about looking for subs, https://www.wassenaar.org is not a bad place to start.
In 1941 the world realised that the battleship was far outranged by aircraft, who were able to attack it long before the battleship was able to get close enough to the carrier to be able to use those 'powerful 16-inch guns'. At that moment, the battleship became obsolete. The biggest battleship ever, the 'Yamato', was no match whatsoever against carrier-borne aircraft.
The US still can't get into its head that the days of the carrier are gone now too. It will take an 'Arizona', 'Repulse' or 'Prince of Wales' kind of incident to change that policy. No need to spend 12 billion on a white elephant any more.
At the present time, lots of small ships with big missiles are the way to go. They pack as much punch as a super-carrier, but they are cheap and easily replaceable.
Why buy a 'Ford' when you could have a dozen or more equivalents for the same money?