[The following, by Barry Rubin, is crossposted from The Rubin Report.]

What is the United States and the world going to do about an act of aggression by North Korea on South Korea, the deliberate unprovoked firing of mortars at civilians? And what are the lessons of this situation for other world problems?

First, nobody is going to do anything real in response to this attack. Indeed, the South Koreans are lucky that they aren't being investigated and condemned for something or other.

That last remark, of course, was a sarcastic reference to Israel's treatment though it also applies to other cases, for example the Russian attack on Georgia; the way the UN backed down in Lebanon to Syria and Hizballah pushing around the UN peacekeeping force; Iran's covert warfare against American forces in Iraq and Afghanistan; Pakistan openly sponsoring terrorism against India while India is unable to retaliate; and other recent cases.

If countries not only get away with aggression but their victims are blamed if they retaliate or defend themselves, the level of aggression in the world will rise. If aggression is perceived as low-cost and victorious than the level of aggression in the world will rise.

Until recently, these points were regarded as an obvious principles of international affairs that would have been repeated in every university course and the editorial pages of all major newspapers.

So, should the United States do something dramatic and punish North Korea? This leads to the second principle. If the United States were to do so, a full-scale war would erupt. Understandably, the West is not prepared for such an outcome and unwilling to pay such a price. American forces are already tied up in other missions. The North Koreans know this.

Here is lesson two:

If an ideological, ambitious dictatorship knows that by threatening war and conflict, by using military force, or threats, or terrorism, it can get whatever it wants than it will do so.

During the nineteenth century, great powers went around the world with gunboats and other forces. They seized countries and territories. If one of their citizens was molested they would have their fleet bombard the enemy capital. This was called imperialism.

In the twenty-first century, people are still wrapped up in thinking about that framework, in apologizing for such behavior, in trying to be good global citizens.

Meanwhile, though, there are now small and medium powers that go around their region with money, arms' supplies, covert operations, ideology, and terrorism. They have endless grievances. Refusing to make peace or deals that would bring stability, they use their willingness to fight and die to blackmail their opponents; they even use their "race" and religion to blackmail their opponents.

In effect, they transmit the message: I'm tough, I'm "crazy" in your terms. I'm not afraid to die. You touch me and I'll blow your head off. Make my day, punk.

Thus, lesson three:

European imperialism was like a boxing match in which a much bigger fighter beat up a little guy. What's going on today is like a judo match in which a much smaller fighter beats up a bigger guy who doesn't know how to defend himself or is unwilling to do so.

Of course, no discussion of the situation would be complete without including the element of nuclear weapons. Hence lesson four:

If a state has nuclear weapons and people think it is willing to use them than that country can do whatever it wants.

This is the true point of Iran getting nuclear weapons: not to fire them off at the first opportunity (though this is possible) but to make itself invulnerable. When Iraq invaded Kuwait, the world chased it out. Whatever Iran does once it has nuclear weapons, nobody will do anything about it.

I call this the Defensive Umbrella for Aggression. Iran's regime will get nuclear weapons and ever after it can do pretty much whatever it wants without concern of retaliation from the United States or any coalition of powers.

Finally, I've been to South Korea and met with top officials there. The main conclusion from that visit was the intense frustration of people who have not been allowed to defend themselves. The United States controls the intelligence information South Korea receives, the weapons it can have, and the actions it can take in self-defense.

America does have a right to be involved in these decisions since it guarantees South Korea's existence and provides thousands of troops to defend it. The United States does not want a war to erupt on the Korean peninsula that would drag it into involvement. This is understandable. Yet if the South Koreans had more autonomy earlier perhaps things wouldn't have reached this point.

So this is one more lesson:

The United States and Europe must help their local allies to defend themselves, not always tie their hands and restrict their ability to do so.

Like other contemporary issues and crises, the events in Korea have generated massive discussions and coverage. Yet also, as in these other cases, the inability to learn the most basic lessons from such developments makes it inevitable for more--and even worse--things to happen.