Iran frees a Chinese-American scholar in exchange for a U.S.-held scientist.

Prisoner exchange rare diplomatic breakthrough with U.S.

DUBAI, United Arab Emirates — A Princeton scholar held for three years in Iran on widely criticized espionage charges was freed Saturday as part of a prisoner exchange that saw America release a detained Iranian scientist, a rare diplomatic breakthrough between Tehran and Washington after months of tensions.

The trade on the tarmac of a Swiss airport saw Iranian officials hand over Chinese-American graduate student Xiyue Wang for scientist Massoud Soleimani, who had faced a federal trial in Georgia over charges he violated sanctions by trying to have biological material brought to Iran.

The swap, however, had clear limits. Crushing U.S. sanctions on Iran blocking it from selling crude oil abroad remain in place, part of President Donald Trump’s maximum pressure campaign imposed following the U.S. withdrawal from Tehran’s nuclear deal with world powers last year. Those sanctions in part fueled the anger seen in nationwide protests last month that Iranian security forces violently put down, unrest that reportedly killed over 200 people.

Wang’s release had been rumored over recent days. One lawyer involved in his case tweeted out a Bible verse about an angel freeing the apostle Peter just hours before Iranian Foreign Minister Mohammad Javad Zarif broke the news in his own tweet. He posted pictures of himself with Soleimani at the Zurich airport before quickly whisking him back to Tehran by jet.

Trump shortly after acknowledged Wang was free in a statement from the White House, thanking Switzerland for its help. The Swiss Embassy in Tehran looks out for America’s interests in the country as the U.S. Embassy there has been closed since the 1979 student takeover and 444day hostage crisis.

Brian Hook, the U.S. special representative for Iran, accompanied Soleimani to Switzerland to make the exchange. He later posed for a photograph with Wang, who carried a folded American flag in his arms while wearing gray workout clothes.

Hook and Wang traveled to Landstuhl hospital near Ramstein Air Base in Germany where Wang likely will be examined by doctors for several days.

Wang’s wife, Hua Qu, released a statement saying “our family is complete once again.”

U.S. State Department U.S. special representative for Iran Brian Hook stands with released scholar Xiyue Wang in Zurich on Saturday.