Three successive Kim regimes in North Korea have made an art of nuclear brinkmanship on the Korean peninsula. The newest Kim, 33-year-old Jung-un, seems especially intent in recent months on provoking a response from the United States.

His latest attempt was North Korea’s first successful launch of an intercontinental ballistic missile—one capable of reaching Alaska, according to defense analysts. Targets in Japan and South Korea have already long been within the reach of North Korean medium-range missiles. It was not likely a coincidence that the North Koreans tested their most advanced missile as Americans celebrated Independence Day.


In a statement before an emergency meeting of the United Nations Security Council on July 5, the U.S. ambassador to the United Nations, Nikki Haley, called the I.C.B.M. test a “clear and sharp military escalation” and ominously warned that such provocations “are closing off the possibility of a diplomatic solution” to the standoff in East Asia.

This latest, longest-range North Korean missile test, she said, “requires an escalated diplomatic and economic response.”

“The world is on notice,” she told the members of the U.N.S.C. “If we fail to act in a serious way, there will be a different response.” The United States, she said, is “prepared to use the full range of our capabilities to defend ourselves and our allies.”

Even the expanding reach of North Korean missiles cannot morally justify a preventive strike by the United States at this time.

That military threat serves a worthwhile role, hovering above diplomatic pressure on the Kim regime, but Father J. Bryan Hehir believes that even the expanding reach of North Korean missiles cannot morally justify a preventive strike by the United States at this time. The Trump administration, he adds, should remain extremely careful about how it talks about a possible response to the ballistic thumb-nosing of the unpredictable Mr. Kim. Father Hehir is the secretary for social services for the Archdiocese of Boston and a professor at Harvard University’s John F. Kennedy School of Government. For decades he has been a key advisor to the U.S. bishops’ conference on peacemaking and international security.

Discussing Ambassador Haley’s comments at the United Nations on July 6, he says, “I think people have to watch their words in this situation. It is not unlike the Syria crisis, where you say, ‘XYZ,’ and back yourself into a corner and then not have the option except to do what you said you would do—even though you might not have thought it through.”

From Father Hehir’s perspective a hypothetical preventive strike against North Korea fails a test for moral legitimacy on three “just war” grounds: All other options to conflict have not been exhausted; the expectation of success is weak; and, finally, any strike would initiate a conflict that would lead to a level of noncombatant suffering last witnessed during one of the 20th century’s world wars.

It may be tough for saber rattlers in Washington or on Twitter to accept, but patience and caution ought to continue to guide the Trump administration’s response, according to Father Hehir. “We have not satisfied the last resort criterion in that there are other ways to continue to deal with this problem,” he says, including new diplomatic and economic pressure. In terms of the probability of success, he points out that because its nuclear capability is unclear and its nuclear forces hidden away in deep mountain bunkers or dispersed on mobile launching platforms, “it is very hard to conceive of a use of force that would completely eliminate North Korean nuclear capacity.”

Finally, “whenever you think of the use of force on the Korean Peninsula, the dominant [just war] category that stands out here is proportionality. That is, if there ever is a case where the use of force is justified, you still don't fight a war that causes more harm than good.” It is hard to imagine, he explains, that containing North Korea’s hypothetical threat to the United States could be morally balanced against the devastation a renewed conflict would cause to South Korea and Japan. “We have to take into consideration what could happen to our allies.”

South Korea’s capital Seoul, with 26 million people in its metro area, is a mere 35 miles from the demilitarized zone where 70 percent of Pyongyang’s conventional military capacity is crowded. According to the U.S. Department of Defense, a second Korean War could mean 200,000 to 300,000 South Korean and U.S. military casualties within its first 90 days, in addition to hundreds of thousands of civilian deaths. Another assessment predicts that should Pyongyang “live up to its threat of turning Seoul into a ‘sea of fire,’ casualties in the larger Seoul metropolitan area alone may surpass 100,000 within 48 hours.” A South Korean simulation in 2004 put the figure as high as 2 million civilian casualties in the first days of renewed conflict.

“We spent 40 years [confronting] a much more powerful adversary and found a way through it. That ought to be burned into the minds of decision makers” in Washington.

With the prospect of open conflict so unpalatable, the United States has little choice morally but to continue a “multidimensional and multilateral” campaign to encourage the North to change its bellicose ways, according to Father Hehir. The Trump administration should continue economic and diplomatic initiatives, he says, while encouraging a multilateral response, drawing in the Russian Federation and the People’s Republic of China—nations which share an interest in peace on the peninsula—as much as possible.

That is no easy task, as North Korea seems increasingly resistant to appeals even from close ally China and when deeper economic isolation threatens to only cause greater harm to the North’s already famished public, he admits. All diplomatic efforts should be orchestrated through the United Nations, according to Father Hehir.

The United Nations has played a pivotal role in the Korean drama since the beginning; it was through the United Nations that the U.S. and allied intervention in East Asia was justified in 1950. Its resolutions and its charter on the use of force should continue to oversee the crisis, according to Father Hehir. “We still have an unfinished war,” he says. “That is one of the things that the North Koreans seeks to resolve.”

Despite his strong belief that just war principles do not justify renewed conflict, Father Hehir does believe that military force has a key role to play in this geopolitical drama. As discussions continue, the threat of the possible use of military force should focus the North’s attention, he suggests. A similar deterrent threat, after all, kept the peace between the United States and the Soviet Union for decades. And, he adds, just because one nation may make a threat, “you do not have to immediately move to it”—something he hopes the Trump administration keeps in mind.

The idea that Mr. Trump may feel obliged to turn to the military option because of his tough talk on North Korea during the campaign riles Father Hehir. “That would be utter nonsense,” he says. Handling North Korea requires “intelligence, restraint and patience.” Now holding the position of the leader of the world's greatest military power, President Trump has obligations and responsibilities different from those of candidate Trump, he argues. “You can’t say I have to do something because I said so during the campaign.

“We spent 40 years [confronting] a much more powerful adversary and found a way through it,” he adds. “That ought to be burned into the minds of decision makers” in Washington. The president’s personality and lack of background on geopolitical issues “certainly give one pause,” Father Hehir says, adding, “you cannot handle this situation with one-liners sent out of the blue.”

He hopes the president listens to more seasoned voices on world affairs in his administration like Secretary of Defense James Mattis and National Security Advisor H.R. McMaster, as next steps are discussed, urging that those today clamoring for a more muscular approach to North Korea should be disregarded. “There were voices in 1950s who called for the use of nuclear weapons with China and Russia,” Father Hehir recalls. “That would have been a disaster,” he says, “and we would have been condemned by history.”

There is still plenty of time and negotiating room, he says, to avoid that fate today in Korea.

Correction (6:20 p.m., July 7): An earlier version of this report conflated the meaning of the term "pre-emptive strike," conducted when enemy aggression appears imminent, with "preventive strike," undertaken to neutralize a potential threat.