destructiveness of modern anti-trade warfare

We all know how destructive the German unlimited submarine warfare was during WW1 and WW2, and also the effective blockade of Japan via the American submarines in the pacific theatre.

Nowadays, things have changed. My point is, the submarine threat seem to be much greater than ever before, due to various changes after WW2.

Major changes:

1: Cargo ships are now HUGE, compared to those in the ww2 era. Oil tankers, Liquified Natural Gas carriers, iron ore carriers, container ships etc. all huge. This means the loss of a single ship would be comparable to the loss of dozens or even hundreds of smaller ww2 era commercial vessels.

  1. sonar much more advanced: the newest British submarine, Astute, can detect surface ship in New York from its base in england. This means modern submarines have GREAT detection range, and since commercial vessels are not designed for stealth, they are loud targets and easily detected by passive sonars.

  2. Submarine’s attack range much greater: modern attack subs are usually armed with anti-ship missiles, and commercial vessles have no ability to intercept nor is it stealthy enough, and they are not designed for survivability either. This makes them extremly vulnerable to missiles.

  3. modern subs more stealthy: subs nowadays are much more difficult to detect and sink, and more costly, because you have to drop so many sonobuoys by airplanes, surface detection is no longer effective because modern subs do not need to surface, and even those that do (diesel-engined) have developed AIP.

  4. modern economy more dependent on trade: this means the importance of trade is greatly elevated and hence its disruption by submarine warfare would be much more serious than before.

I think in a modern war, the sub threat on commercial trade would be so much more profound than before.


Well, using your example of WWI, one of the advances which made Germany much more resistant to blockade was the development of the Haber process. I’ve read that extended the war by at least a year (of course the Nazis instead of hailing him as a national hero, drove him out because he was Jewish…too bad they didn’t denounce his work too, maybe that would have shortened the war in Europe).

My only point is that many materials of war which once depended upon digging them out of the earth or growing them have been supplanted by man made materials, eg rubber.

On the other hand today, I’d bet much of our newer arsenal depends upon rare earths imported fro China.

Yes absolutely unrestricted submarine warfare on commercial shipping would devastate the global economy within weeks. However you have the same MAD (mutually assured destruction) incentives to prevent that, the Chinese economy would collapse without western consumers to buy the export goods they make. Russian and US economies would collapse without the stream of cheap imports from China and the rest of asia.

No one can afford to get off the treadmill.

Its also hard to imagine a scenario where unrestricted submarine attacks on commercial shipping wouldn’t escalate to all out conventional warfare and then Nukes, at which time the collapse of the global economy won’t really matter.

This sounds like the premise for a Bond film :wink: The commies weren’t the enemy it was businessmen gone ary!

Both of which are also much more destructive than their WWII equivalents.

Historian John Keegan, after decades of study of war and warriors:

Yes, there would be lots of losses but there are other factors.

While there are huge ships, there are also tens of thousands of smaller ships, not that many submarines or an unlimited number of missiles, torpedos. Lots of sea area and shallow costal waters.
Not that many subs, costly and slow to build.
Even nuke subs have to come in somewhere for food and maintenance.
You hit a container ship with a missile. Which container(s) get hit? You have 10,000 or more on some ships. Missiles don’t automatically go for the waterline or engine room. Tankers. Iran hit a few with missiles back in the 80s. Most survived.

The subs give away their position with each launch. Other subs tracking them now have a good target. Surface and air anti-sub warfare is pretty good once they have a specific area. Active sonar is real trouble for any sub.

Looking for opinions? IMHO. Moved from General Questions.

samclem, Moderator

This. The targets are fewer, but the hunters are fewer as well. They also rely on a more fragile infrastructure-- even nuke boats have to find a way to replenish ammunition, and even the biggest powers rely on a limited number of bases (and even fewer at-sea tenders) to support them. Back in WWI and WWII (at least the early days) you could always save your torpedoes and rely on deck guns to dispatch merchantmen; nowadays, you’re using a very expensive war-load to take down ships.

Plus, as it’s said, the largest modern cargo vessels and double-hulled tankers are robust targets; one torpedeo or sub-launched missile may not be enough to guarantee a sinking, which further limits the destructive power of submarines.

That said, I’m glad we don’t have any serious reason to fear this scenario.

Cite please. I find myself very skeptical.