Iran nuclear deal

U.S. Secretary of State John Kerry (right), along with British Foreign Secretary Philip Hammond (left), speak to reporters in London on May 12. They tried to assure European banks they won't be penalized for conducting legitimate business with Iran. Critics say it should not be up to the U.S. to encourage investment in Iran. Josh Lederman/AP hide caption

CIA Director John Brennan discussed ISIS, the FBI-Apple dispute over an iPhone, the state of the Iran nuclear deal, and his future plans as President Obama's term draws to a close. Ariel Zambelich/NPR hide caption

Iranian shopkeepers in the main bazaar in the capital, Tehran, in September. Iranians are eager for economic sanctions to be lifted and have been moving quickly to meet their obligations under a nuclear deal, according to analysts monitoring the agreement. Atta Kenare/AFP/Getty Images hide caption

Iran's President Hassan Rouhani leaves after a televised speech in Tehran on Dec. 16. Iran has been dismantling parts of its nuclear program as required under an international deal, and some sanctions could be lifted as soon as January. Ebrahim Noroozi/AP hide caption

Ali Akbar Salehi, top, the head of Iran's Atomic Energy Organization, delivers a speech as lawmakers and officials discuss a bill on Iran's nuclear deal in parliament on Sunday. The parliament approved an outline of a bill allowing the deal's implementation. Ebrahim Noroozi/AP hide caption

Undersecretary of State for Political Affairs Wendy Sherman testifies before the Senate Foreign Relations Committee in 2014. Sherman was the lead U.S. negotiator on the Iran nuclear deal. She stepped down from her post last week and is now teaching at Harvard. Charles Dharapak/AP hide caption

Iranian President Hassan Rouhani prepares to speak with NPR's Steve Inskeep on Saturday in New York. Rouhani reaffirmed Iran's commitment to the nuclear deal and said his country would be willing to discuss Syria's future with the United States — after ISIS is defeated. Bryan Thomas for NPR hide caption

An Iranian man walks past a mural displaying an outline of Iran, adorned in the colors of the country's national flag, on June 29 in Tehran. A large majority of Iranians appears to support the nuclear deal. Bherouz Mehri/AFP/Getty Images hide caption

President Eisenhower (left) visited Iran's Shah Reza Pahlavi in Tehran in 1959. The U.S. had begun working with Iran to launch its nuclear program two years earlier and would provide Iran with its first nuclear research reactor in the 1960s, at Tehran University. AP hide caption