Before even delivering his big speech Thursday night in Cleveland, Trump was sending tremors through America's allies, threatening to turn generations of U.S. foreign policy on its head, and even breaking with longstanding Republican tradition.
He told The New York Times
that he would not guarantee the U.S. would come to the aid of its NATO allies, let's say in case of a Russian invasion. Instead, he said he would consider their payments to the United States before offering protection.
This transactional approach to national security would be a massive shift, and indeed prompted a response from Estonia, whose president indignantly tweeted from the Baltics that it had come to America's defense after 9/11, no questions asked.
Indeed, NATO Secretary General Jens Stoltenberg was forced to remind Trump
that NATO had kept the peace in Europe since World War II -- good for Europe, and good for the United States.
Even the Republican Senate Majority Leader, Mitch McConnell, said he disagreed with Trump on NATO
'Harmful to the United States'
I asked Mike Rogers, Former Chairman of the House Intelligence Committee, what a new NATO doctrine would mean.
"It certainly would be a violation of the charter if you said you haven't paid, we're not showing up."
Protectionism, he said, would be "harmful to the United States, harmful to our allies."
Afterwards, he said he just hoped Trump didn't mean what he was saying, and would instead find wise counsel to whisper in his ear.
Trump doubled down in his convention speech, filled with retrenchment protectionism and isolationism. He said the U.S. would "walk away" from the North American Free Trade Agreement if negotiations failed to produce "a much better deal for America."
Former Mexican President Vicente Fox was scathing when I asked him on Thursday what pulling out of NAFTA would mean.
"The loser is going to be the United States," he told me.
"Mexico imports from the United States over $750 billion every year. We import, we buy from the United States."
"That means over 10 million jobs for U.S. citizens. So you don't lose jobs by trading. You gain wealth and opportunities to your people."
Trump's threats to slap tariffs on China has sparked concern in Beijing's halls of power, and prompted economists to warn of recession and job losses in the region and the United States.
Trump and the Middle East
Trump began the foreign policy part of his acceptance speech with Iran -- invoking the specter of a humiliated Washington signing the Iran nuclear deal, "one of the worst deals ever negotiated."
It's an image that most analysts find hard to reconcile, since for the past year during which time the deal's been in force, Iran has been deemed in full compliance
, its nuclear program severely limited, and global security enhanced. War avoided.
On diagnosing the Syrian war, Trump will find agreement among allies in the region on this point: "Another humiliation came when president Obama drew a red line in Syria -- and the whole world knew it meant absolutely nothing." (That, of course, was President Obama's pledge to intervene should Assad use chemical weapons
; a pledge he did not follow through on when those weapons were used.)
But Trump says he wouldn't go after al-Assad before destroying ISIS, only to insist, in an interview with CBS 60 Minutes
, that he would want "very few troops on the ground" to defeat ISIS.
He offered solutions such as "we're going to have unbelievable intelligence," and nothing much different to the current Obama administration strategy there.
On refugees too, Trump proposed a world of retrenchment. The war in Syria has produced the worst refugee crisis since World War II
Trump: 'No right to lecture'
He told the convention that immigration from any country that has been "compromised by terrorism" would be immediately suspended. He says there's "no way" to screen refugees.
In fact, U.S. officials tell me, Syrian refugees face the most stringent background checks of almost anyone trying to enter the U.S.
This foreign policy segment was full of what a Trump presidency would not do, and where it would not go.
Unlike past Republican presidents -- Reagan or both Bushes -- there was no appeal to moral leadership or spreading freedom and democracy around the world.
To the contrary, Trump insists that the United States has no "right to lecture" autocrats like Russian President Vladimir Putin or Turkey's Recep Tayyip Erdogan.
"I think right now when it comes to civil liberties, our country has a lot of problems, and I think it's very hard for us to get involved in other countries," he told The New York Times.
"I don't know that we have a right to lecture."