Stardate 20030331.1532

(On Screen): In the early stages of American involvement in WWII, the US unleashed its submarines on Japan. The goal was to do to them what the Germans had come dangerously close to doing to the UK with its U-boats.

Japanese anti-submarine warfare capability was never really very good, and in the early part of the war it was particularly dreadful. One reason for this was that the Japanese had incorrectly calculated the depth to which American boats could dive. They set their depth charges based on that, and the American submariners soon learned that if they dove deep enough (at depths well within the safety limit of the boat hulls) they would be all but immune to Japanese depth charging.

Obviously this was quite useful and interesting, and it began to be talked about back on shore, in a "Boy, have you heard about how stupid the Japanese are?" kind of way. The story spread, and spread, and it eventually ended up in a newspaper. And then one Congressman included it in a speech before Congress.

As might be imagined, the Japanese heard about this, and started setting their depth charges to go deeper. This prompted an officer in the Navy to send a letter to the Congressman saying that he was sure the Congressman would be pleased to learn that the Japanese had corrected their mistake.

Out of that experience, and a couple of others like it, submariners soon learned that they couldn't ultimately trust anyone who was not in subs. It wasn't that others might necessarily be inimical, but that they might be careless or stupid.

They came to be known as the "Silent Service". Submarine officers didn't wear their dolphins when in the O-club, and though they would be friendly and would talk about irrelevant subjects, they would not talk about what they did to anyone. They would talk, but never talk shop. They might not even admit that they were in subs.

Submarines live by stealth. And submarines are, by their nature, unforgiving. What would be minor damage to a destroyer could be fatal to a sub.

In most theaters in WWII, less than 20% of casualties actually died. But in subs, almost all casualties were deaths, usually "missing and presumed dead". And in general, when submariners died, a lot died at once. When the boat went down, everyone in it was doomed. There are only a few cases in which a sub was lost and left some survivors.

Usually what happened was that a boat would go out, radio back regularly, and then go silent, and not return, and at the time there was usually no way of knowing what had happened to it. In some cases it was possible to determine after the war what had happened to a sub which never returned, through Japanese records, but the fate of some of them has never been determined to this day. (In a few cases it's thought that they encountered minefields and were destroyed without any witnesses, but we'll never know.) And in all of those cases, every man in the boat died.

So submariners learned that it was better to not tell others about what they did, because even little pieces of information might leak out and eventually reach the enemy. The benefits of talking were small and the risks non-negligible.

And submariners are reticent to this day, for the problem remains. The best defense for a sub is when you don't know where it is, don't know what it can actually do, and don't know what it intends. It's a big ocean out there and a sub is very small. Subs are snipers; they hunt and kill and slip away into the darkness – or they don't get away, and die.

Often that meant that they didn't get public credit until much later for what they'd done. But it's important to do; getting credit and publicity is not critical. An enemy carrier sunk by a sub was out of the war, even if there was no newspaper headline at home giving the sub credit. (And American subs sank a surprisingly large number of Japanese carriers, as well as being responsible for more total Japanese shipping losses than everyone else combined. For example, at the Battle of the Philippine Sea, Japan lost three carriers. Two of those were sunk by American boats.) That publicity would have carried the risk of revealing operational information about the subs which might have increased the considerable danger they faced.

American submariners had a greater chance of dying in combat than any other major assignment in the US military. 25% of the men who served in subs were killed in action. Lapses in security could have made that figure even higher. When you live by stealth, you have to labor in the shadows.

That's the case for the Special Forces, too. If anything, they're even more vulnerable. The best defense for a sub is the fact that it's a small fish in a really big ocean, and it's damned hard to detect a sub even if you have a pretty good idea where it is. But when the Special Forces are operating in a combat zone, and are in areas nominally under enemy control and outnumbered thousands to one, they only really survive as long as the enemy doesn't suspect they're there. If the enemy knows a SF team is in a general area, and decides to get them, that SF team is in pretty big trouble unless it can manage to get extracted pretty rapidly.

And the Special Forces also have something of a reputation for not really talking about what they do. Certainly it's important during actual combat operations for their assignments to not be publicized. It's not just that you