EDITORIAL: Calculating the threat from North Korea

OPINION:

“The land of the morning calm” is anything but that. The ancient Korean name for the divided peninsula is belied by the tension simmering for nearly 70 years, enlivened with frequent bursts of cross-border invective and sometimes violence.

It threatens to erupt into something worse again, now that the United States has a president who takes seriously the erratic behavior of a dictator. North Korea armed with nuclear weapons is not merely an Asian Syria, but a nation with nuclear weapons of its own. Donald Trump must proceed with a careful eye, a keen ear and stay on the right side of the thin line between bluster and authentic provocation.

Five years as the petulant leader, Kim Jong-un has surpassed his father and grandfather for manufacturing outrage. Three generations of nuclear ambition are reaching fruition with the assistance of a fellow rogue in Iran.

The conjoining of nuclear capability with ballistic missile delivery tests has made the North’s periodic threats to rain nuclear destruction on an American city a greater-than-remote possibility. That’s something that President Trump, with his determination to “make America great again,” refuses to let slide. Aggression anywhere is a warning of aggression everywhere, and like it or not, dealing with it is the unique responsibility of the superpower. In short order Mr. Trump has answered Syria’s use of chemical weapons and dispatched an aircraft carrier battle group to a station off the Korean Peninsula.

He makes no apologies for his bold approach to resolving persistent problems, nor should he. “I explained to the president of China that a trade deal with the U.S. will be far better for them if they solve the North Korean problem!” Mr. Trump tweeted (with his trademark exclamation point) on Tuesday morning, and continued tweeting: “North Korea is looking for trouble. If China decides to help, that would be great. If not, we will solve the problem without them! U.S.A.”

Rodong Sinmun, the official government newspaper in Pyongyang, responded with another nuclear threat: “Our revolutionary strong army is keenly watching every move by enemy elements with our nuclear sight focused on the U.S. invasionary bases not only in South Korea and the Pacific operation theater but also in the U.S. mainland.” Anniversaries are important in Asia, and with the birthday of Kim Il-sung, the nation’s founder, on Saturday, the grandson might well mark the occasion with a sixth nuclear test.

American intelligence has struggled since the ’90s to gauge with accuracy Pyongyang’s progress toward a functional nuclear weapon, and Kim’s underground explosions and rockets have demolished the smug assurances that there is nothing to fear in the near term. The Trump administration is covering, as it must, a wide range of eventualities. The White House rightly observes that the North Korean “threat” is no threat at all if it is not credible, and H.R. McMaster, the National Security Adviser, says the Navy’s voyage toward Korea is “prudent” and “that what must happen is the denuclearization of the Korean Peninsula.”

Several American presidents have allowed North Korea’s succession of “dear leaders” to play games with them, but the new president is not a willing participant in a game with nuclear weapons. Understanding the Korean culture is an acquired skill, and more complicated than the West sometimes recognizes. Vigilance is the right response to enemies that bear America ill.