In 1953, Iran’s democratic government led by Prime Minister Mohammad Mosaddeq was toppled by a military coup backed by the CIA and the British Secret Intelligence Service. Mosaddeq had nationalized the British-controlled Iranian oil industry, and the Americans and the Brits weren’t having any of that.

The coup transformed Iran’s constitutional monarchy into a royal dictatorship under Shah Mohammad Reza Pahlavi. The American pet Pahlavi was toppled in turn by a popular revolution in 1979. The toxic relationship between the U.S. and Iran that arose from this history continues to this day.

Iran’s promotion of Islamic revolution throughout the Middle East, including the support of various militias, has not helped reduce the friction. Nor has the country’s development of nuclear technology. Since 1979 the U.S. has applied various economic, trade, scientific and military sanctions against Iran for its perceived mischief.

One bright spot in this dark relationship was the hard-won Iran nuclear deal, an agreement on Iran’s nuclear program reached in 2015. The deal was signed by Iran and the five permanent members of the United Nations Security Council—China, France, Russia, United Kingdom, United States—plus Germany and the European Union.

Under the deal, Iran agreed to eliminate its stockpile of medium-enriched uranium, cut its stockpile of low-enriched uranium, and reduce the number of its gas centrifuges for 13 years. It agreed to limits on enriching uranium and building any new heavy-water facilities for the next 15 years. The International Atomic Energy Agency (IAEA) would have regular access to all Iranian nuclear facilities to ensure compliance.

In return, Iran was to receive relief from the U.S., European Union, and UN Security Council nuclear-related sanctions. The deal not only put a brake on the potential of yet another nuclear power, but offered promise of an improvement in U.S.-Iran relations.

Then came President Donald Trump. In May, 2018, even though the IAEA said there was no evidence Iran was not in compliance with the agreement and Americans strongly supported it, Trump withdrew.

The remaining parties expressed interest in maintaining the agreement but, with the U.S. out, Iran lost interest and has lifted the cap on its stockpile of uranium, increased its enrichment significantly and resumed activity at nuclear facilities that were previously prohibited. The Biden administration has attempted to revive the deal but so far without success, not surprisingly given the American vacillation. According to a top French diplomat involved in the deal, “We are back to square one.”

Not only has Iran reverted to expanding its nuclear capacity, it has strengthened its position in the region, even normalizing its relations with former enemy Saudi Arabia.

Its proxies from Hamas to Hezbollah to the Houthis are making their presence felt, launching attacks from Israel to Lebanon to the Red Sea, even coming into conflict with U.S. forces. Perhaps most importantly, Iran has drawn closer to two of the nuclear deal’s signatories, China and Russia, selling oil to the former and weapons to the latter—two superpowers now sanctions-busting customers.

Sanam Vakil, the director of the Middle East and North Africa program at Chatham House, has said, “I see Iran as well positioned, and it has checkmated the U.S. and its interests in the Mideast.”

If the Americans were hoping to pull back from the Middle East in order to focus on China, that may now be off the table.

This thanks in no small part to Donald Trump. If he’s re-elected in November, we could look forward to more of the same—a president who admires dictators and holds America’s democratic allies in contempt. Americans may decide they can afford his nonsense. The rest of the world can’t.