The Providence Journal (R.I.), July 29:

Donald Trump, a former reality TV show star who somehow has become a major political party’s nominee for the presidency, contemplates shaking up the world order in a way no president has imagined for the last 67 years.

Specifically, he challenges the notion of American obligations to the North Atlantic Treaty Alliance, or NATO, the coalition of 28 European and North American governments that formed in 1949 to protect member nations against external threats, seen mostly in those days as emanating from the Soviet Union.

Hillary Clinton, by contrast, understands that America has an essential role to play in the world in defending the nation’s security and that of its allies.

“An attack on one is viewed as an attack on all,” according to Article 5 of the NATO charter, in which members vow to unite for the collective defense. That article has been invoked exactly once in the last 67 years: When terrorists attacked the United States on Sept. 11, 2001.

Now comes Trump, a survivor so far of the American political process, but certainly no historian, diplomat nor strategic global thinker. He told The New York Times recently he wouldn’t necessarily support a NATO member being invaded by its enemies. He would first assess whether that member had “fulfilled its obligations” to NATO and the United States.

If it had, he said, then, yes, he would order U.S. forces to support it.

This is a first.

Trump has said many things that are implausible, offensive or simply false. They are, indeed, part of his outsider appeal to a swath of primary voters who made him the Republicans’ nominee. But this time, he is saying something that is potentially catastrophic.

The mutual defense structure that was established in the wake of World War II has helped keep the peace ever since. It is true that many member nations haven’t fully met their financial obligations to the alliance, leaving it to U.S. taxpayers to pay more than their fair share – one of the costs of being the world’s greatest superpower and its bulwark of representative democracies. If Trump’s statement serves any useful purpose, it is that it should help compel delinquent members to pay up.

But the world Trump invites us to join is a dark and fearful place. He would place the United States in a figurative foxhole, hunkered down as mortars and rockets fly overhead, emerging to fight only if certain contractual terms are met. One of the most important functions of NATO is to make it clear to Russia that the West will respond if its member states are attacked – thus deterring it from making such attempts. Do we really want Russia to be confused on this point?

Imagine a morning in which Americans awoke to the news that Russian tanks had rolled into Riga. Do we want a president whose impulsive, angry and amoral nature makes it questionable whether he can balance domestic and foreign interests, weigh diplomatic and human risks and invoke – or refuse to invoke – military power?

No. We don’t.