The most disturbing point in President Trump's speech to the U.N. General Assembly on Tuesday was not when the audience laughed at him.

That's not to say the laughter — at Trump's egotistical (and fact-challenged) list of his domestic achievements — wasn't justified.  We Americans have gotten used to Trump's ceaseless boasts that turn every speech into a pitch to his domestic base. Foreign leaders are less inured.

So it's disconcerting to hear an audience of prime ministers and presidents, including many longtime allies, snicker at Trump. It tells us that after a year on the world stage, the president's self-aggrandizement has made him a global figure of fun.

Even more disturbing was Trump's embrace of the kind of populist nationalism that led to world wars in the last century and ethnic civil wars in this one. "We reject the ideology of globalism and accept the doctrine of patriotism," the president said. "America will always choose independence and cooperation over global governance, control, and domination."

This formulation is not only ignorant of history but undercuts Trump's own goals.

Let's start with history. As French President Emmanuel Macron pointed out, in a speech that rebuked Trump, rabid nationalism led to two world wars.

To prevent a third such war, the United States helped build multilateral political and economic institutions. These included the United Nations and the precursors to the European Union, which helped keep the peace in Europe for 70 years.  They also included NATO.

"Nationalism always leads to defeat," Macron said passionately. "If … the international order becomes fragile … this can lead, as we have already seen twice, to global war. We saw that with our very own eyes."

So the "ideology of globalism" is not some nefarious plot by Lilliputians to trap an American Gulliver.  Not only did Washington create the postwar order, it has a veto over just about every multilateral group to which it belongs.

The idea that such institutions exert "global domination" is the kind of nonsense that used to be propagated by nutcase militias that believed unmarked U.N. "black helicopters" were secretly patrolling America as a prelude to a takeover.  Perhaps this phrasing isn't so surprising, considering that much of Trump's speech was written by Stephen Miller, a xenophobic conservative who has spearheaded the president's immigration policy.  This rhetoric is being fed daily to Trump's base.

Yes, postwar multilateral organizations badly need reform.  But Trump makes clear his disdain for anything multilateral, including NATO. He actively undercuts the European Union and wants to blow up multilateral pacts in favor of bilateral deals. He prefers one-on-one summits with adversaries like North Korea, Russia, or China, where he thinks he can best their leaders (and can ignore his briefers).

And his fetish for unilateralism undercuts the goals he set out in his U.N. speech.

Let's start with Iran, the main target of Trump's wrath this week.  The president has pulled the United States out of the nuclear deal negotiated with Tehran by Washington and its European allies, and endorsed by the U.N. Security Council.  Trump's rationale: The deal failed to address Iran's work on missiles or its aggressive behavior in the region, and had a sunset clause that would eliminate key curbs on Tehran's nuclear program after 10 to 15 years.

Trump wants the European allies to restore sanctions against Tehran, as Washington will do in early November.  But they have so far refused, saying (correctly) that Iran hasn't violated the pact's terms.

More to the point: At Trump's request, the Europeans had been working hard on a second deal with Tehran, trying to address Trump's concerns. Key Trump advisers proposed giving the Europeans a chance; had they failed, they would have been open to restoring sanctions.

Instead, Trump stiffed the allies and went it alone. Now he must battle the Europeans, along with China and Russia, on the sanctions issue — undercutting the united front needed to curb Iran in the region.

Similarly, Trump has undercut global cooperation needed to keep tight sanctions against North Korea. His one-on-one lovefest with Rocket Man led Russia and China to weaken sanctions pressure before Kim Jong Un shows any readiness to eliminate his nukes.

Moreover, as Macron rightly noted, global cooperation is vital to curbing Russian digital warfare and Moscow's support for chemical-weapons use in Syria and against its political opponents abroad. (Trump barely mentioned Russia at the United Nations.)

And why would Trump start trade wars with European allies and China at the same time when he needs a united trade front to have any chance against Beijing?

Answer: Trump's "doctrine of patriotism" is an ego trip, drawn from his core belief that everyone is out to take advantage of America. It ignores the need to uphold international rules used to confront adversaries. It undercuts America's standing as a global leader.

The tittering U.N. audience got it. Rather than putting America First, the president's speech was all about Trump.