What shall we make of North Korea's attack on the small South Korean island of Yeonpyeong? Well, by the everyday standards of International relations, a 90-minute barrage of over 200 artillery shells that killed at least two South Koreans and wreaked havoc on a civilian town would justifiably be described as what it so obviously is: a crisis and an act of war.

But in the Alice in Wonderland world of U.S. policy toward the Hermit Kingdom, all the White House can summon itself to do is "condemn" the attack. Worse still, South Korea's president, Lee Myung-bak, who swore an oath to protect his country, has threatened retaliation for a future attack, but nothing for this one.

Some will see all this as commendable restraint. Others will chalk it up to a desire for re-engagement at the negotiating table. But were I Kim Jong-il, I'd take the obvious cue and plot my next act of war.

There have been unconfirmed reports that Kim Jong-il and the heir and custodian of his strange legacy, his son Kim Jong-un, visited the very region where the attack on Yeonpyeong was launched, bolstering the point that this was a pre-planned attack and not simply a response to South Korea's military exercises in the same region. Others argue that the barrage relates to the publication of reports on a new uranium processing plant that emerged over the weekend.

But is it really necessary to hunt for clues and motives? After decades of dealing with North Korea, we still have almost zero understanding of the regime or its motivations, beyond a desire for self-preservation at all costs. Perhaps what we ought to focus on, then, is the larger narrative of which this attack counts as but the latest installment.

What is indisputably clear is that North Korea has been acting more and more aggressively, especially over the past year. Last summer the country again set off an atomic explosion and launched a fusillade of missiles. In March of this year, it plainly sunk a South Korean naval vessel, killing 46 sailors without consequence. Now it has launched its first attack on South Korean territory since the Korean war.

To rational observers, this should be an alarming trend. Eventually, the North may miscalculate, spiraling off into uncontrolled conflict with the South and probably the United States military.  Or perhaps its continued attacks on South Korean civilians will culminate in such pressure on the South Korean government that Seoul itself responds in a militarily significant way.

Even if that doesn't happen, the North has clearly ratcheted up the stakes, and we ought to expect it to become all the more aggressive if the international community exacts no price. Here, the likelihood of significant action ranges from slim to none. That, in turn, means more attacks and more casualties. The United States would prefer talking to fighting--or, truthfully, mounting a response of any kind. That's a laudable notion, but not one appropriate for dealing with a regime as heedless, infantile, and aggressive as Pyongyang's. It views, not without reason, diplomacy as pure charade. Without any appreciable pressure from China on the regime, the United States and its allies have no other leverage they’re willing to use.

Can a show of force, even moving U.S. military forces closer to the besieged island, make a difference in Pyongyang's calculations? We don't know, but we do know what doesn't work. At some point, democratic governments have a responsibility to uphold some very basic norms of international behavior. Advertising our fears as if they were virtues, we have so far failed, blatantly and even ostentatiously, to do so in response to almost any North Korean provocation.

If we refuse to do so, at some point we may awaken to find ourselves embroiled in a costly, bloody, and, most of all, unnecessary war.

Michael Auslin is a resident scholar in Asian studies at the American Enterprise Institute.