One of the toughest beats in the intelligence business is North Korea. You can drive yourself nuts trying to come up with a coherent theory of why they’ve done this, that or the other thing and what it portends. The sad truth is that we just don’t know much about what one analyst calls "the nutty norks." Case in point: This week’s artillery attack on Yeonpyeong Island.

Some experts have dismissed it as a mere bid for attention. This theory notes that the Kim Jong Il regime needs American and Republic of Korea aid to survive. Since 2001 we’ve been preoccupied with Iraq and Afghanistan. The Dear Leader doesn’t like playing second banana. From time to time, he needs to remind us and our ROK allies of what a threat he really is. Our usual response is to beg North Korea to re-engage in talks. Then, we provide them with more aid in return for more illusory promises.

It’s a plausible theory.

Other experts think this is a demonstration of the military resolve of the successor. Kim Jong Il has appointed his 26-year-old son as a four-star general in the Inmun Gun. There are rumors that the Dear Leader is ill. It seems to be a tradition that the dictator’s son proves his military prowess by engaging in outrageous provocations, thereby proving to the North Korean military that he is courageous enough to lead them. If you lead the North Korean military, you lead the country.

This is a plausible theory, too.

Another school of thought thinks this is desensitization therapy. We tell the North Koreans that they can’t have nuclear weapons, and they build a plutonium bomb. We tell them that they can’t enrich uranium, and they install 2,000 centrifuges at Yongbyon (and invite a prominent Western scientist over to verify their achievement). They sink an ROK Navy warship, the CheonAn, and nothing happens. Now they shell ROK territory. We’ll continue to stay calm and not over-react, even as they’re marching into Seoul.

This theory may not be wrong.

The problem with all of these theories is that they are based on our perceptions about the behavior of a rational nation-state. They assume some clever and over-arching agenda.

I submit that we should be looking at this event through the eyes of the North Koreans. If we do, the explanation may be rather mundane.

This attack occurred on an island in the West (Yellow) Sea. Although there is a clearly defined Military Line of Demarcation on land, there is no clearly defined line running into the ocean.

The so-called Northern Limit Line has never been accepted by North Korea, and has been the subject of many skirmishes over the years. A look at a map shows that Yeonpyeong Island is rather close to North Korea. The ROK Navy was dropping shells in nearby waters as part of its annual Hoguk military exercises which, like all military exercises, are condemned by the North Koreans as a provocation and rehearsal for invasion. North Korea suffers no military slights. If you throw a water balloon at them, they will send back a hand grenade. If you shell their waters, they will shell your land and kill your civilians. A response of this type was entirely predictable.

That doesn’t make it right, and I am no apologist for North Korea. The point is that when one views this event from the mindset of the other side, it is perfectly understandable. The grand theories attempting to explain it are gaseous. The real story is that the North Koreans saw the ROK Navy’s actions as a provocation and responded as they might well be expected to.

So now what?

North Korea is moving inexorably towards the acquisition of a uranium bomb and the intercontinental delivery capability that is its raison d’etre. It isn’t there yet, but it is making steady progress. Arms control doesn’t work. Bribery doesn’t work either. The ROKs have figured this out, and are fed up. They are beginning to sense an existential threat to their security. ROK President Lee Myung Bak acted with restraint after the sinking of the CheonAn, even though his countrymen and his military were infuriated. He can’t play this card again. He has already called for massive retaliation. By the time this commentary reaches publication, we may well know what his massive retaliation will be.

For many years, the U.S. kept an infantry division on the border. Although the official story was that it was to be a "tripwire," the real U.S. role was to keep the South from going North. That division is gone now. The restraints have been removed. In a second Korean War the US will provide air and naval power (in which it is clearly superior), but not many ground troops.

Although China publicly claims to be like "lips and teeth" with North Korea, the truth is that China would be delighted if the Kim dynasty went away. Mr. Kim is bad for business. China is not antagonistic to the ROK, although it does not want to encourage American adventurism in its back yard. It can cut a deal with the ROK.

Japan is just plain scared. In a second Korean war, the North Koreans have threatened to turn Japan into "a lake of fire."

Japan has been a lake of fire before. There is no love lost between Japan and either of the Koreas, but ultimately Japan will stand with the US/ROK alliance. It has little choice.

Sooner or later, there will be a second Korean War. It will be awful for Korea, and probably for Japan, too. The shelling of Yeonpyeong Island may be the opening gun, or it may be just another of many sensational incidents that lead to the next war.

Of course, this is just another plausible theory. I wish I really knew.