Can North Korea hit American cities?
One thing is certain: North Korea is plowing considerable resources into building its nuclear capability. And it is clearly making progress – even if Tuesday’s failed missile test shows it still has a long way to go.
Japanese officials said what appeared to be a conventional Musudan rocket, which theoretically has the ability to reach Japan and the U.S. territory and military base of Guam, exploded either as or shortly after it left its launcher. North Korea is estimated to have some 20 to 30 of the missiles – first deployed in 2007, but yet to be launched successfully.
What North Korean leader Kim Jong Un wants, most analysts believe, is simple – a rocket that can fire a nuclear warhead at least to regional targets. His ultimate ambition, however, is to be able to hit U.S. cities on the West Coast, most likely from a submarine that could hide itself at sea.
This has the potential to cause tension between America/Japan and South Korea over responding:
Still, once the first nuclear-armed submarine exists, Japan and the United States might feel political pressure to destroy it.
That would come with considerable risks. The North is known to have huge volumes of conventional artillery based along the South Korean border, much of it in range of Seoul and its 10 million residents. The risk of those weapons inflicting massive casualties is one of the key factors that has deterred multiple U.S. administrations from considering the kind of preemptive strike on Pyongyang’s weapons programs that the United States has threatened against Iran.
The problem is that if America and/or Japan hit North Korea's nuclear missiles and infrastructure to preempt a threat to either of our homelands, North Korea can begin to level Seoul with the vast array of conventional artillery poised north of Seoul across the DMZ.
As long as North Korea didn't have the means to hit America or Japan, this problem could be put off.
But will America and Japan decline to act if South Korea won't help out of fear for Seoul?
I doubt it. Japan really doesn't want to be nuked a third time and we probably have a moral duty to help Japan avoid that (not that nuking Japan in 1945 wasn't justified) even if we aren't within range yet.
And if America and Japan hit North Korea's nukes to protect their cities, South Korea will need to invade North Korea at least a little bit to protect their main city and capital.
We all have different objectives (here's a take on China's interests) and North Korean long-range nukes will put those differences into sharp focus.
UPDATE: Strategypage discusses the North Korean threat:
The offensive threat comes from a few crude (so far) nuclear bombs, Cold War era chemical weapons and lots of artillery. North Korea could not win a war with this type of force, but because Seoul (the southern capital where half the population and a quarter of the GDP are) is so close to the border, North Korea has lots of targets within range of rockets and artillery.
If North Korea wants to do more than destroy Seoul, they hope the initial bombardment and a large-scale commando attack collapses the South Korean army and allows the North Korean army to road march to Pusan. That's not likely but that's their plan, it seems.
The bombardment threat is real, however:
The southerners know the north is desperate and heavily armed. What do you do? South Korea has responded by increasing its ability to quickly halt any rocket and artillery bombardment from the north. This would involve a lot of accurate South Korean artillery fire and smart bomb use in a short time.
I personally have my strong doubts that precision strikes can knock out the North Korean artillery before Seoul is wrecked. The Israelis failed to pull that off in 2006 against a more feeble threat.
I still think marching north of the DMZ to occupy the land in artillery range of Seoul is the answer. That will take time, too, but it has the advantage of not just letting North Korea prepare for another round in a few years after South Korea spends money on reconstruction.