National security adviser John Bolton. (Nicholas Kamm/AFP/Getty Images

NEW YORK — U.S. and Iranian leaders traded insults in public at the U.N. General Assembly this week, but that’s a minor skirmish compared to the coming battle between the two adversaries. The U.S. government is about to launch its toughest sanctions yet to tighten the noose around the neck of the Tehran regime — a bold but risky gambit that places America opposite its oldest allies.

Over the next four weeks, the Trump administration will finalize and deploy a series of measures to exclude Iran from international financial markets, erode the Iranian economy, and keep cash out of the hands of the Iranian government and military. By Nov. 5, all countries and international companies will have to choose between doing business with Iran or the United States. This is the Trump team’s best chance to hit Iran hard, short of military action.

Will it work? That depends on the goal. President Trump says he wants Iran to return to the table to strike a “better deal” than the one President Barack Obama struck and that Trump pulled out of.

“It doesn’t matter what world leaders think on Iran,” Trump said Wednesday. “Iran is going to come back to me, and they’re going to make a good deal. I think, maybe not. Deals, you never know.”

Based on Iran’s own statements, that seems unlikely. But at the very least, the strategy could deny the regime funds it uses to spread misery across the Middle East.

While Iranian President Hassan Rouhani was calling Trump a “Nazi” and a bully in his speech at the United Nations on Tuesday, several top Trump administration officials were laying out the U.S. policy path at the conference of United Against a Nuclear Iran, a nonprofit organization that opposed the Iran deal.

Matching Trump’s own bellicose rhetoric, Secretary of State Mike Pompeo and national security adviser John Bolton lashed out at Iran and the European Union, which announced Monday that it will work with Iran, Russia and China to set up a special payment vehicle specifically designed to skirt coming U.S. sanctions.

Pompeo said he was “disturbed” and “deeply disappointed” by the European Union’s move and accused America’s allies of enabling Iran’s support of terrorism and the regime’s corruption. “This is one of the most counterproductive measures imaginable for regional and global peace and security,” he said. “I imagine the corrupt ayatollahs and the IRGC [Islamic Revolutionary Guard Corps] were laughing this morning.”

Of course, almost everyone inside the General Assembly was laughing Tuesday morning — at President Trump’s claim that he has accomplished more than any other U.S. president — but that’s not what Pompeo was referring to. Bolton, instead, mocked the European Union, expressing skepticism that it will be able to pull off the financial maneuver.

“The European Union is strong on rhetoric and weak on follow-through,” he said.

Bolton warned that between now and Sept. 5, all countries and international entities must reduce their purchases of Iranian crude oil to zero and cut off all transactions with Iranian financial institutions, or face new and harsh U.S. sanctions. He specifically mentioned SWIFT, the international financial clearinghouse, which the Trump administration is considering sanctioning as well.

SWIFT and other actors “must take a good, hard look” at the business with Iran and ask themselves if it’s worth the risk, Bolton said. His message to Iran was clear: If you think America is the “Great Satan,” the Trump administration is prepared to play that role. “If you cross us,” Bolton said, “yes, there will indeed be hell to pay.”

There’s confusion about what Iran would have to do to avoid the coming storm. Trump has said he is willing to sit down with Rouhani any time, but Pompeo insists that Iran first make progress in 12 different areas of its domestic and foreign policy, changing the very nature of the regime and its actions. Nobody believes that’s going to happen anytime soon.

Pompeo’s new special envoy for Iran, Brian Hook, who led negotiations with European countries on the issue before Trump pulled out of the deal, defended the rhetoric and offered another goal for the sanctions: stopping Iran’s regional violence.

“If talking to Iran kindly worked, we wouldn’t be in this position,” he said. “We need to restore deterrence, especially in the Middle East.”

In other words, even if Iran doesn’t come back to the table, the “maximum economic pressure” will hurt its ability to consolidate power and expand influence in Iraq, Syria, Lebanon and Yemen. If the Trump administration can’t change Tehran’s calculus, it at least wants to keep America’s boot on the regime’s neck.

That’s a worthy goal, but it would require a multilateral, comprehensive and sustainable strategy to succeed. Sanctions are not going to push Iran out of Syria. Over time, even the strongest economic pressure wanes and sanctions lose their bite. Former secretary of state John Kerry reportedly advised the Iranians to wait out the Trump administration. Like it or not, he’s probably right.

In the coming months, Iran will be the test case for the foreign policy Trump has long yearned for: unabashed unilateralism, disregard of alliances and the arrogant use of American power to compel world actors’ cooperation with unpopular policies. The open question is, what happens if it doesn’t work?

Will Trump back down or escalate further? Will our allies be there to help? Will our adversaries take advantage? The Iranian threat is real, but Trump’s approach is risky. If it fails, the consequences will be no laughing matter.

Read more:

Dana Milbank: Trump is the laughingstock of the world

Karen Tumulty: Trump’s America is a bully, not a beacon

Hassan Rouhani: Iran is keeping its nuclear commitments — despite Trump

Max Boot: Iran is much smarter than Trump