North Korean state media has issued a statement saying that they successfully tested a submarine-launched ballistic missile (SLBM) earlier this week in the Sea of Japan. They said the test is meant to bolster self-defense.
The test was conducted off the coast of the city of Wonsan in what the
statement described as “vertical mode.” The North Koreans said it posed
no danger to any neighboring country’s security.
The US, however, was quick to criticize the test as a provocative
action, and suggested that North Korea needs to show more restraint.
They followed this by testing an ICBM fired across the Pacific Ocean.
South Korea and Japan also issued statements complaining that the North
Korean test was in violation of the UN Security Council, though it isn’t
entirely clear this was the case. North Korea is presenting this purely
as a defensive test.
The important thing to take away is that this is a *submarine* launch. North Korea has a lot of submarines, although most of them are too small to launch missiles.
Put a nuke on a submarine launched missile and bingo – you have “second strike” capability – meaning that even if your country loses a war, you can inflict unacceptable damage on your opponent in retaliation.
Israel has done this, too, allegedly.
Now I don’t believe North Korea would ever launch a nuclear missile at the US before or during a war with the US, because the retaliation would annihilate North Korea.
*But*, if the US were to *win* a war with North Korea, any surviving military might order a strike against the mainland US using a surviving submarine as “payback”, regardless of the consequences.
And of course it’s possible a submarine missile might be used against a US fleet involved in a US war against NK, but again the consequences for NK would probably be unacceptable to them.
Bottom line: This is a significantly enhanced capability for the North.