You have to wonder if there will ever be a generation of Americans who aren't concerned about the war-threatening antics of North Korea.

The Korean War effectively ended with a truce in 1953, but 57 years later, North Korea remains belligerent. Why can't it be like Vietnam, which, 35 years after the war there ended, has become a U.S. trade partner with lofty ambitions to become an economic power in Asia?

Vietnam, when it was divided, was also China's protégé. But while North Korea is as dependent on China as it ever was for food and fuel, Vietnam has stretched that cord. In fact, although friendly, Vietnam and China are also antagonists in a territorial dispute concerning a group of islands in the South China Sea.

It's hard to envision North Korea ever becoming capable of standing on its own. For decades, its leaders have kept the country mired in some alternate reality in which they shake their fists at the rest of the world from time to time while ignoring that their people can't even feed themselves.

But North Korea's tantrums can't be ignored. Two weeks ago, it shelled Yeonpyeong Island because South Korea had conducted artillery tests there. Two South Korean marines and two civilians were killed. In March, 46 South Koreans were killed after a warship, the Cheonan, was hit by a torpedo apparently fired from a North Korean submarine.

As bad as those incidents were, more significant is what could be new efforts by North Korea to grow its nuclear arsenal despite its promise five years ago to end such a program. A recent revelation that the North is enriching uranium is a slap to the five other nations, including China, that participated in the negotiations leading to North Korea's promise.

Speculation by observers suggests these moves are related to an expected leadership change in North Korea. In recent months, Kim Jong Il has promoted the youngest of his three sons, Kim Jong Un, to the rank of general and given him more civilian authority. Provocative moves similarly occurred before the elder Kim assumed leadership in 1994.

China remains the key to bringing some sense of reason to North Korea's government. Without China's support, the impoverished nation would quickly fall into disarray, which is something China does not want to see since it likes the buffer the North provides between it and South Korea, a staunch U.S. military ally.

Almost as strongly, though, China wants to maintain an amiable relationship with its trade partner, the United States. That gives this country some leverage beyond the mostly wringing of hands it has displayed so far.

"Now is the time for China to step up," said U.S. Joint Chiefs Chairman Adm. Mike Mullen. That point must be pressed by President Obama when his Chinese counterpart, Hu Jintao, visits Washington in January. Obama and Hu spoke by telephone after the Yeonpyeong Island shelling. But there was no subsequent rebuke of North Korea by Hu.

Unless China acts more decisively, North Korea will never change. U.S. influence on China is limited, but it must play the cards it has to move it in that direction.