With the successful implementation of the historic nuclear agreement between Iran and the P5+1, a new chapter has opened between Iran and the international community, including the United States. Nevertheless, the future path of bilateral relations between the United States and Iran is uncertain and many challenges exist as the two countries attempt to formulate new terms of engagement. What should U.S. policy be towards Iran after the nuclear agreement? Can the agree­ment open the door to effective collaboration on areas of mutual interest, especially given the rising security challenges and rapidly changing dynamics of the Middle East? Or, will strategic rivalries between Iran and the United States con­tinue to shape and impede cooperation?

In this January 19 New Atlanticist blog post, Atlantic Council staff writer, by Ashish Kumar Sen, interviews Harvard Kennedy School professor and former US diplomat, R. Nicholas Burns. Burns says that Iran nuclear agreement is positive for the United States, but Iran will continue to be a problem in a violent Middle East.

This book chapter discusses in theory the various ways that religion and political parties can intersect, and then consider three sets of cases that have provoked considerable scholarship in recent years – Christian Democratic parties in Europe, religion and parties in the United States, and Islamic parties in the Middle East

“This is one of the most urgent and important challenges for our country, for our European allies as well as for Israel and our Arab partners in the Middle East. The United States must do whatever it takes to thwart Iran’s nuclear weapons ambitions and its determination to become the dominant military power in the region.

We should thus marshal our diplomatic, economic and military strength to block Iran now and to contain its power in the region in the years ahead.

With that strategic aim in mind, I support the Iran nuclear agreement and urge the Congress to vote in favor of it in September.”

Professor Nicholas Burns, a former point man on Iranian nuclear matters, talks with The Wall Street Journal's Washington Bureau Chief, Gerald Seib, about why he advocates effort to contain Tehran’s regional ambitions.

It is no accident that hardly anyone involved in the Iranian nuclear negotiations has expressed optimism about meeting the November 24 deadline for a comprehensive agreement. The Iranian and U.S. governments are continuing to meet regularly -- most recently last week in Vienna -- but there are few signs of meaningful progress. Indeed, the essence of the deal that has always made most sense -- a rollback of the Iranian nuclear program in return for a rollback of sanctions -- seems increasingly beyond reach. Instead, the Iranians have been insisting on a rollback of the sanctions in return only for limited transparency on their industrial-size nuclear program. But Washington has insisted for a long time that, given Iran’s past violations of the Nuclear Nonproliferation Treaty (NPT), limited transparency won’t be enough. Further, it has already stated that it will not accept an industrial-scale program, although it is prepared to agree to a limited-enrichment capability.

"While a threat to U.S. interests, the Islamic State of Iraq and al-Sham (ISIS) presents us with a unique opportunity to 'reset' the Middle East equation—to actively transform regional relations, to abate the cold war between Iran and Saudi Arabia and to forge a new working relationship with Iran," writes Payam Mohseni. "As the United States moves to escalate its war against ISIS and forge a coalition against the terrorist group, it is important that Iran be included in the process. After all, U.S. and Iranian interests have increasingly converged in the Middle East with the emergence of a common enemy, and no power in the region is better suited to taking on ISIS than Iran and its affiliated Shi’a militias in Iraq."

"The U.S. should seize the opportunity presented by the Iraq crisis to reach out and engage Iran. The threat posed by ISIS and radical jihadism as well as the potential for further regional instability represent important areas of mutual strategic concern for both countries. By engaging the Iranians, the U.S. will gain the critical ability to shape the course of events without getting bogged down in the conflict. It will also help the U.S. build a working relationship with Iran that could ease the current nuclear negotiations forward and lay the groundwork for future cooperation when a successful deal is reached."

Having finalized details of the interim deal to freeze Iran's nuclear program for six months in exchange for limited relief from sanctions, Graham Allison notes that attention is turning to the question of "end states" for a comprehensive agreement. In these negotiations, he asks, "what can the United States realistically hope to achieve?"

"...[S]anctions played a part in changing Iran's behavior, but not because they forced Iran to return to the negotiation table out of fear of economic collapse. Rather, sanctions contributed to a transformation of the balance of power within the Iranian political system that had been already underway since 2009 — prior to the enactment of the current sanctions regime. Sanctions helped pave the way for a Rouhani victory in the 2013 presidential elections..."