Since Iran’s 1979 revolution, the country has never had a more effective diplomat than current foreign minister Mohammad Javad Zarif, said Carnegie’s Karim Sadjadpour on BBC Newsnight. In contrast to many Iranian diplomats, Sadjapour said, Zarif spoke “not as a fire breathing ideologue, but as a nationalist,” and has done a very effective job of articulating Iran’s national interest.

The big question people will have is how much control over Iran’s nuclear program someone like Zarif has, Sadjadpour continued. To what extent Zarif and Rouhani are able to deliver on their promises and whether Iran’s Revolutionary Guards are fully on board with this interim agreement remains to be seen as well. He emphasized that the success of nuclear agreements is judged over a period of months and years, not over a period of minutes. With the Iranian population eager for to have economic sanctions lifted and to rejoin the international community, it will be tough for members of Revolutionary Guard to go against this enormous popular will, Sadjadpour concluded.

This interview was originally aired on BBC Newsnight.