Donald Trump has threatened to redraw the map of the Middle East—and one international-relations expert says the implications should be powerful enough to end his presidency.

The crisis intensified Tuesday morning when the 80-year-old president posted a map on Truth Social labeling the Strait of Hormuz as “new U.S. territory.”

The narrow waterway, one of the most strategically important shipping routes on Earth, is not American territory. It runs between Iran and Oman, with its waters falling under the sovereignty of those two countries while remaining subject to international navigation rights.

Yet Trump’s post appeared to transform a military confrontation into something even more explosive: an apparent threat of territorial conquest.

Roughly two and a half hours later, the president announced that peace negotiations with Iran were over.

“There are no talks or conversations going on, or scheduled, with the Islamic Republic of Iran,” Trump wrote.

He declared that the U.S. naval blockade would remain “in full force and effect” and claimed that the Strait of Hormuz was open, operating and cleared of water mines.

The two messages—one portraying the strait as American territory, the other terminating diplomacy—sent a chilling signal at a moment when the region was already balancing on the edge of wider war.

Mark Copelovitch, a professor of political science and public affairs at the University of Wisconsin, described Trump’s conduct as potentially presidency-ending.

“I’m just a small-town international relations professor,” Copelovitch wrote, “but I think it should be a huge, presidency-ending scandal that the President of the United States regularly violates the UN Charter by threatening the territorial conquest of other UN member-states and our NATO treaty allies.”

His judgment is an expert’s political and legal assessment, not a formal finding that Trump has committed an impeachable offense. A social-media post alone does not transfer territory, and no international body had recognized Trump’s purported claim.

But the legal principle Copelovitch highlighted is foundational.

Article 2 of the United Nations Charter establishes the sovereign equality of member states and prohibits countries from threatening or using force against another state’s territorial integrity or political independence.

The rule was designed to prevent powerful nations from simply seizing land or waterways because they possessed the military strength to do so.

Trump’s critics argue that his message strikes directly at that postwar order.

If the United States can declare part of Iran and Oman’s territorial waters to be American, they warn, then Russia, China and other powers could use the same logic to justify expansion against their neighbors.

“Maybe we, as Americans, have just decided that our government’s signature and ratification of treaties doesn’t matter, because we’re special and can just do whatever we want in international relations,” Copelovitch wrote sarcastically.

“Fine. But then we must expect all other countries can do that, too.”

The Hormuz threat also fits a broader pattern.

Since returning to office in January 2025, Trump has discussed acquiring or controlling a startling list of foreign territories and countries. Eric Columbus, a senior editor at Lawfare and former Obama administration appointee, pointed to Canada, Cuba, Gaza, Greenland, the Panama Canal, Venezuela and now the Strait of Hormuz.

Some of those statements may have been negotiating tactics, political theater or deliberate provocations. But repeated often enough—and backed by the military power of the United States—they can no longer be dismissed as harmless jokes.

The Strait of Hormuz carries roughly one-fifth of the world’s oil and gas during normal peacetime operations. Any attempt to annex or permanently control it could provoke Iran, alienate Oman, destabilize global energy markets and place American forces in direct confrontation with regional powers.

Oman has traditionally acted as an intermediary between Washington and Tehran, making Trump’s territorial claim especially alarming. Rather than protecting a neutral route, the United States would be threatening the sovereignty of a diplomatic partner whose cooperation could be crucial to ending the war.

The administration may argue that Trump was merely emphasizing U.S. military control over shipping lanes and mine-clearing operations—not issuing a literal legal annexation.

But his decision to use the words “new U.S. territory” makes that distinction dangerously difficult.

Maps have consequences. So do presidential declarations.

For Trump, the image may have been another display of dominance—an attempt to show supporters that America had conquered a strategic prize.

For his critics, it was evidence of something far darker: a president openly treating international borders as obstacles that American power can erase.

Trump declared diplomacy dead only hours later.

Now the world is waiting to discover whether the map was propaganda, a threat—or the first public glimpse of what he intends to do next.