Sub Crash by Robert Ludlum

We should thank the British and French navies. They took the unthinkable and made it possible. No longer do you have to wonder if two submarines crashing into each other is even plausible, thus providing the impetus to finish your terrible political potboiler about a Jack Ryan-ish figure having to stop a war and recover nukes after two submarines hit each other. Get it done quick, Tom Clancy has already spent the morning churning out his version, it'll be at the printer's tomorrow. Yes Virginia, apparently two machines carrying dozens of nuclear warheads and navigating by sonar can hit each other in an ocean.

A cross-channel investigation has been launched after two submarines carrying nuclear weapons – from the Royal and French navies – collided in the Atlantic.

HMS Vanguard and Le Triomphant crashed on February 3 or 4, despite both vessels being equipped with sonar.
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Armed with 16 ballistic missiles, it is now believed to have been towed last night to Faslane, a nuclear submarine base in Scotland, with dents and scrapes to its hull. A senior Navy source was quoted in The Sun as saying that the potential consequences of such a collision would be "unthinkable".
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"It’s very unlikely there would have been a nuclear explosion," the source told The Sun.

"But a radioactive leak was a possibility. Worse, we could have the crew and warheads. That would have been a national disaster."

Does this happen often? Are subs constantly hitting other ships, denting precious whales, or knocking over the majestic spires of the castles of undersea societies? It seems to me, what with sonar and everything, a submarine 20 feet away from you shouldn't just "sneak up on you", let alone completely baffle two separate captains. Ah well, it seems perhaps America doesn't need to spend as much as it does on being the world's greatest navy, we just need to set up some rudimentary obstacles around our coastlines. It'll protect us from incursion from British and French submarines at the very least.