By Mick Krever, CNN

Want proof that Iran’s president-elect wants to change Iran’s foreign policy?

“Literally every diplomat that Ahmadinejad fired for favoring engagement with the U.S. was later on hired by Rouhani in his think tank,” Vali Nasr, a former member of Obama’s foreign policy team told CNN's Christiane Amanpour on Monday. “So he’s been working on this.”

Add to that the fact that Rouhani has a track record on the international stage, as a former chief nuclear negotiator, and Nasr is convinced that diplomats around the world have been given the gift of “breathing room” by the election of the new Iranian president.

“Rouhani was the architect of probably the most forward-leaning position Iran ever had on the nuclear issue back in 2003,” Nasr said. “And he’s held onto that view.”

At the time, Rouhani led the voluntary suspension of Iran’s nuclear program. Ultimately, the program was started back up. It could be difficult, opined Nasr, for Rouhani to repeat such a step.

“He’s once-bitten, twice-shy,” Nasr told Amanpour. “In other words, he’s not going to stick his neck out for it to be chopped off.”

The United States and its allies have been given the opportunity to “try something new with Iran.” It is Nasr’s hope that the Obama Administration takes the plunge.

“Rouhani can’t come to the table seriously unless the indication is that he can deliver more than Ahmadinejad,” Nasr said.

In order to “sell a deal back home,” Nasr continued, he must show that he can make progress on the issue that most Iranians really care about: economy-crippling sanctions.

In exchange for the suspension of Iran’s nuclear program, he said, the United States has offered little more than aircraft parts and “modest permission” to trade gold and silver.

“Rouhani has to be able to show Iran’s supreme leader and revolutionary guard that the reformists can actually get the United States to offer these things,” Nasr said. “That’s how you build momentum for reform in Iran.”

AMANPOUR: New Day for Iran and the United States?