Re: Where?
but that doesn't mean we can just fire a torpedo at it when he first shows up [in international waters, anyway]
Why not? Back in the days of the Cold War proper, before over-the-horizon radar, and when radio capabilities were less advanced, both sides would opportunistically or even deliberately plan-and-execute a shoot down of the other side's aircraft in remote locations to try and glean intelligence on flight, defence capabilities or to examine the wreckage. All in breach of various laws and treaties, but so long as you weren't caught, it didn't count. U2 spying flights in Soviet airspace fell into the same innocent-unless-caught category, until the Ruskies showed they could shoot them down.
In this case, if the USN destroyed a Nork submarine seventy miles of the US coast, publicly nobody would know, nor care. And if wreckage or bodies were found then it could be attributed to an on-board explosion caused by poor equipment. Obviously if the USN sank a Chinese sub in error there'd be some embarrassment, but with the Norks restricted to clanky old 1950's design Kilo class diesel electric subs, I think the USN wouldn't have that problem.
Biting the hand that feeds IT
