Hold your breath, world. Donald Trump might yet become U.S. president.
Polls indicate most Canadians, and most of the world outside the United States, wouldn't pick Mr. Trump if they were Americans. And there's a particular reason non-Americans should worry: If he becomes president, he won't be the Leader of the Free World.
Most Americans never realized that that presumptuous unofficial title often rankles in other countries. But the truth is the United States is a leader, and the backbone of alliances in the Atlantic and Pacific. Many countries, from Canada to Lithuania to South Korea, depend on it.
If he's elected, Mr. Trump would be just the kind of president to weaken that. American power hasn't been faultless, but the world would lose with a president whose inclinations are impulsive and retaliatory but also unreliably isolationist. Allies can't depend on him.
Mr. Trump's own statements should make those allies doubt, but so too should his unpredictability. If you're a national leader, and the United States is no longer a reliable guarantor of your security, you start to look for new arrangements. You might get closer to other powers, like China or Russia, or develop new weapons, even try to get the bomb.
"I hear from folks involved in national security in Europe and in Asia serious worry about, is the U.S. going to be engaged at all in playing a leadership role?" Michael Chertoff, the former secretary of homeland security under George. W. Bush, said in interview in Ottawa, where he attended the Centre of International Governance Innovation's Global Policy Forum. Mr. Chertoff, once the Republican counsel in the Senate's Whitewater investigation, endorses Hillary Clinton – he's one of many Republican former national-security officials who warn Mr. Trump would be a "reckless" choice.
For Canadians, security is not such a direct concern. We have oceans to each side and bilateral North American security arrangements wouldn't change dramatically. Canada is more worried he'd tear up trade deals or muck up the border. "But you know, Canada's part of the world," Mr. Chertoff said. "If things are deteriorating in the Middle East, if we're getting more failed states, if Russia's becoming more dominant in Europe, that's going to have an effect on Canada, as well as the U.S., as well as the whole world."
If you are in Eastern Europe, you worry that Russian President Vladimir Putin annexed part of Ukraine and uses disruptive tactics, from hackers to energy-supply bullying, to try to draw countries away from "the West" into Russia's orbit. If you're in Japan, you think about China's rising power and expanding claims to maritime territory.
Donald Trump has questioned U.S. commitment to NATO. He's talked about his admiration for Mr. Putin. That makes Eastern European allies nervous. Maybe they'll start to worry about criticizing Russia, or imposing sanctions, or opposing Moscow's will. In fact, Mr. Trump has suggested all U.S. allies will have to pay up for protection. He has said Japan and South Korea should consider getting nuclear weapons. Maybe they will.
For some national leaders, it might be politically damaging to stand beside a president who says "I like waterboarding a lot." But their bigger concern is an unpredictable ally might force hard choices.
Think about what Canada would do if its trade grew uncertain: If a President Trump might tear up NAFTA and gum up U.S. borders with extreme vetting, Canada would work harder at other trade ties. You'd bet on free-trade talks with China moving faster.
Of course, we don't actually know what Mr. Trump would do. He has said one thing and its opposite about Japan getting nuclear weapons, for example. He has no doctrine. That just makes him more unpredictable.
Mr. Chertoff's big fear is Mr. Trump's temperament. "I'm concerned we're going to have somebody who is impulsive, prone to personalize decisions and not particularly interested in the details" he said. In other words, Mr. Trump does what he feels, based on who he likes. He seems to admire Mr. Putin, so he might act on that rather than strategic calculus. Allies can't predict. And in wide swaths of the world, countries count on a predictable U.S. for their security. They won't breathe easy with Mr. Trump. They're holding their breath now.