President Trump let the world know at the U.N. today that he’s sticking to his vision of America-first sovereignty, rather than cede power to U.N. multilateralists — to their great dismay. Too bad for them: Mr. Trump’s approach is working.

“America will always choose independence and cooperation over global governance, control and domination,” he told world leaders at the UN General Assembly. This country “will not tell you how to live or work or worship.” But we “ask that you honor our sovereignty in return.”

Mr. Trump specifically questioned the International Criminal Court’s authority to adjudicate war crimes, vowing to “never surrender America’s sovereignty to an unelected, unaccountable, global bureaucracy.”

Smart move for the United States. Such a court can’t be trusted; Americans and their allies could be at risk from unjust rulings it issues.

Yet all that only fueled the globalists’ rage. “Multilateralism is under fire precisely when we need it most,” huffed Secretary General Guterres, of Portugal, at the opening of the festivities. Turtle Bay’s usual suspects echoed the sentiment. Without mentioning Mr. Trump, they talked up the supposed wonders of globalism.

Yet, compelling facts on the ground are on the U.S. president’s side. The best example: the 2015 Iran nuclear deal.

Start with the fact that it was signed by none of the seven countries that negotiated it, let alone ratified by their legislatures. Instead, the U.N.’s Security Council endorsed it, turning the Joint Comprehensive Plan of Action into international “law.”

Iranians, he added, “are rightly outraged that their leaders have embezzled billions of dollars from Iran’s treasury” and “seized valuable portions of the economy” to “line their own pockets and send their proxies to wage war” across the Mideast and beyond. Mr. Trump wisely withdrew from it. On Tuesday, he correctly called it a “horrible” deal that let the Iranian leadership “spread mayhem across the Middle East and far beyond.”

Wait, counters the European Union’s foreign-policy czar, Federica Mogherini. “Iran has continued to fully and effectively implement its nuclear-related commitments” under the JCPOA.

Iran’s president, Hassan Rouhani, got nods of approval as he scorned Mr. Trump for “confronting multilateralism.” That’s “not a sign of strength,” he bellowed, but “a symptom of the weakness of intellect.” New U.S. sanctions are “economic terrorism,” you see.

He reminded fellow globalists that the Iran deal is backed by a Security Council resolution (2231, if you’re keeping score). And he thanked those countries refusing to “acquiesce to the U.S. government’s unilateral and illegal withdrawal from the JCPOA.”

On Monday evening, European, Russian, Chinese, and Iranian foreign ministers, the EU’s Iran-favoring Mogherini, and Tehran’s ever-smiling Javad Zarif vowed to save the JCPOA from Mr. Trump’s ire. Their joint statement promised a new banking “vehicle” to evade Washington’s restrictions on using U.S. dollars for businesses with Iran. The new entity would encourage foreign investments in Iran and allow Tehran to export oil even after November, when new American sanctions kick in.

Mr. Trump did say he’d sooner or later negotiate with the Iranians, but first “they have to change their tune.” Mr. Rouhani’s position: Any dialogue must be “in accordance with the rules and norms of international law.”

Well, good luck with that, guys. Fact is, European conglomerates increasingly are canceling contracts and fleeing Iran — as Washington warns they must choose between doing business with America or Iran. By the time Brussels bureaucrats set up that U.S.-bypassing bank, there may be no one left to use it.

Sorry, Mr. Rouhani. Mr. Trump’s ability to leverage America’s economic might against Iran — the world’s utmost terrorist and oppressor of minorities and women — trumps his international deriders.

Globalists may cry foul. But Mr. Trump aims to bend Iran, and his American-first approach is clearly more promising than their oh-so-united Iran-coddling.

This column first appeared in the New York Post.