North Korea's leader, Kim Jong Un, recently celebrated the test firing of a submarine launched ballistic missile (SLBM) -- a "success of all successes" -- and claimed that the U.S. mainland was now within striking distance. Like much else that North Korea's dictator claims, this is largely hyperbole. First, the estimated range of the North's SLBM is about 600 miles, which means that a submarine would have to get relatively close to the U.S. just to be able to strike a coastal target -- and even if parked right off the coast would not be able to reach very far inland. Second, there's no evidence that North Korea has the ability to build a nuclear warhead small enough to fit on an SLBM.
That is not to say that we should be completely unconcerned about this latest development. But neither does it mean that we should be shaking in our boots.
If the Missile Defense Agency is to be believed, all the money that's been spent on missile defense research and development (more than $150 billion since President Reagan gave his "Star Wars" speech announced the Strategic Defense Initiative 33 years ago) has produced an effective missile defense that works. So if that's true (and that's a big if), then the would-be threat from North Korea is less of a threat.
But regardless of the effectiveness of missile defense (which is certainly questionable), the reality is that the U.S. has over 1,400 deployed nuclear warheads capable of striking pretty much anywhere in the world. North Korea has a few warheads (probably less than 10), but -- at least right now -- no ability to strike the U.S. That is what is called overwhelming strategic nuclear superiority. Even if North Korea had a nuclear weapon (or weapons) that could strike the United States, the U.S. could retaliate with devastating effect, i.e., to put it simply: the ability to completely destroy North Korea. This is what is called deterrence. And what kept the U.S. and former Soviet Union from engaging in nuclear war (when both sides had over 10,000 warheads pointing at each other) during the Cold War.
But isn't Kim Jong Un crazy and unstable? Therefore, deterrence wouldn't work. Well, in their time both Stalin and Mao were considered crazy and unstable leaders with nukes, yet they were deterred.
To believe that North Korea would launch a nuclear weapon against the United States is to believe that the regime in Pyongyang is suicidal. Yet, like most dictators, Kim Jong Un ultimately seems more concerned with self-preservation and indulging in guilty pleasures rather than punching a one-way ticket to early oblivion.