One of the U.S. government's top intelligence officials when it comes to Iran, recently retired, has advice for President Donald Trump: Keep the Iran nuclear deal, at least until there's a better option, and maintain a wary eye on the Islamic Republic.

"Maintain and rigorously enforce JCPOA (the nuclear deal, formally the Joint Comprehensive Plan of Action), but if Iran’s leadership remains aggressive, extend its provisions," Norman Roule, who until recently was the National Intelligence Manager for Iran at the Office of the Director of National Intelligence, wrote at The Cipher Brief. "The deal’s important accomplishments should not be discarded without a better plan in hand. A collapse of the agreement will fracture relations with Europe and complicate our efforts against North Korea. At the same time, we should remain adamantine as to Iran’s prompt execution of its obligations. Given Iran’s belligerent actions against its neighbors and our interests, it is not unwise to begin to consider which provisions should be extended to assure the world that Iran cannot shorten the timeline to develop a nuclear weapon or erode international oversight of its nuclear enterprise."

Roule's detailed advice for how to deal with Iran's purported provocations in the region also includes disrupting the logistical chain for the Islamic Revolution Guard Corps (IRGC), a powerful branch of the Iranian military that the U.S. has indicated it could declare a terrorist organization, and to "confront" Iran on the export of its missiles technology to places like Syria and Yemen.

Finally, Roule says the U.S. must engage Iran diplomatically.

"Publicly, we should reaffirm to the Iranian people that only they can choose their government and we will respect that decision," Roule said. "However, they need to equally understand that Iran’s failure to be a responsible member of the international community brings consequences that impact everyone in Iran."

Read the rest of Roule's advice at The Cipher Brief.