For a U.S. president, temperament is destiny, and nowhere was that more evident than during President Barack Obama's trip to Asia last week. Confronted with a series of unforeseen glitches, diplomatic mishaps and potentially dangerous military provocations, the president kept his cool even when sorely tried by circumstances that might have flummoxed a less level-headed chief executive. We couldn't help but compare Mr. Obama's grace under pressure to how GOP presidential nominee Donald Trump might have reacted under similar circumstances, and in a head-to-head matchup there's no question who is better suited for the job.
Start with the minor snafu that greeted the arrival of Mr. Obama's plane at the airport in Hangzhou, China, for a Group of 20 summit meeting. For reasons somewhat in dispute, the portable staircase the U.S. had provided for the president to use when deplaning wasn't in place for his arrival. Mr. Obama found himself stuck on his plane for several minutes until he finally decided to exit the aircraft via a little-used hatch.
How would Mr. Trump have reacted? "I've got to tell you, if that were me, I would say, 'You know what, folks, I respect you a lot but close the doors, let's get out of here,'" he told a group of labor leaders in Ohio on Monday. "It's a sign of such disrespect," Mr. Trump complained, "they won't even give him stairs, proper stairs to get out of the airplane. You see that? They have pictures of other leaders who are ... coming down with a beautiful red carpet. And Obama is coming down a metal staircase."
Mr. Obama, by contrast, brushed off the incident as a minor misunderstanding; he and Chinese President Xi Jinping had bigger things to discuss, for example implementation of the Paris climate accord.
Nor did Mr. Obama pick up his marbles and go home after Philippine President Rodrigo Duterte, who was elected in June, used a coarse epithet to describe Mr. Obama's mother and then threatened to humiliate the U.S. president if Mr. Obama brought up Mr. Duterte's appalling record of human rights violations against suspected drug offenders, including some 2,400 extrajudicial killings in the three months since he took office.
Rather than respond directly to the insult, Mr. Obama mildly suggested that Mr. Duterte was a "colorful character" and went on to question whether the G-20 summit was really "a time where we can have some constructive, productive conversations." A few hours later his aides canceled the meeting. The next day a chastened Mr. Duterte appeared to have gotten the message: "We ... regret [the remarks] came across as a personal attack on the U.S. president," his office said in a statement issued Tuesday.
We can only imagine how Mr. Trump would have responded to a similar contretemps, but we doubt things would have ended well. Mr. Trump and Mr. Duterte are both bullies accustomed to getting their own way while daring anyone to question them. Mr. Obama recognized the folly of engaging in a pointless war of words with someone as obviously unhinged as Mr. Duterte, and doubtless many world leaders would have the same reaction to a President Trump.
But when toughness really counts, Mr. Obama showed that he could hold his ground. He met with Russian President Vladimir Putin on the sidelines of G-20 but refused to sugarcoat relations between the two countries by signing a Syrian cease fire accord proposed by Moscow that would have allowed the continued bombing civilians in Aleppo and other cities.
Mr. Obama didn't say Mr. Putin was acting in bad faith (though he was) or that Russia's support of Syrian President Bashar Assad was prolonging a war that has already killed more than 400,000 people and driven some 6 million from their homes (though it is). Instead, Mr. Obama vowed to keep pressing Russia on the issue. Would Mr. Trump have done the same, or would he have let his open admiration for Mr. Putin get in the way of the best interests of the Syrian (and American) people?
And then there was the North Korean missile launch timed to coincide with the G-20 meeting. Mr. Obama's reaction was entirely appropriate: an immediate denunciation of the test as a violation of U.N. Security Council resolutions and a call for even tougher global sanctions against Pyongyang. It was the most consequential decision the president made during a trip in which Mr. Trump's strongman persona would only have inflamed tensions.
Would a President Hillary Clinton have navigated that set of challenges as deftly as Mr. Obama? We can't say for certain, but after decades of experience in foreign relations, including four years as secretary of state, we can say that she understands the need for proportional, measured responses to provocation. Mr. Trump, whose business career rests on bombast and whose political rise was fueled by tough-guy rhetoric, clearly does not.
In diplomacy, words have consequences, and the words of the president must be precisely calibrated to the national interest. Mr. Trump doesn't seem to understand that a cool temperament and an ability to respond appropriately are among the most important qualities a U.S. president can have. Instead, he's a loose cannon on the ship of state, and that is what makes him so spectacularly unsuited to serve as commander-in-chief.