On April 2, the parties in the Iran nuclear negotiations reached solutions on key parameters of a Joint Comprehensive Plan of Action. As expected, this latest event aroused another round of heated discussion in international media and academia. The agreement should represent major progress, and a diplomatic solution to the decade-long problem has never been so clearly within reach. Many uncertainties still remain, however.

It is truly impressive that the two major parties in the negotiations, Iran and the United States, have demonstrated the greatest determination to resolve the dispute. The past two years have witnessed very frequent direct dialogues and interactions between John Kerry, the U.S. secretary of state, and Mohammad Javad Zarif, Iran's foreign minister. The two spent about a week in Switzerland together from March 26 to April 3 in the run-up to the deal.

It's not easy for either Kerry or Zarif to just put aside all the other important issues they need to deal with. Remember, one of them is in charge of the foreign affairs of the world's biggest superpower, and the other is the foreign minister of a major regional state. Nothing is more illustrative of their resolve than their last encounter in Lausanne, which should be commemorated in the history of international relations.

Kerry and Zarif's joint efforts also suggest that neither the U.S. nor Iran – or at least their administrative teams – can pay the political costs for the failure of their negotiations. This should be good news for the coming rounds of discussion. Given these circumstances, there should be high hopes for the final agreement three months away.

Furthermore, the recently agreed-upon parameters also addressed some of the toughest questions surrounding the issue. They first outline clearer restrictions on the size of Iran's nuclear program with the goal of ensuring that Iran cannot get a nuclear bomb within one year. Under this agreement, Iran can only enrich uranium to a purity level below 3.67 percent, Iran can only have 6,104 of its first generation of centrifuges in operation, and Iran will have to reduce its stockpile of enriched uranium to 300 kilograms from its current 10,000 kilograms.

The parameters then set a timeframe for the agreement. The U.S. side used to contend that the time limit should be two decades, while Iran insisted that it should be less than five years. Under the new parameters, both parties agreed that some of Iran's nuclear activities will be limited for 15 years, some others for 10 years, and the rest for 20 years. The U.S. and Iran both compromised to some extent to arrive at these conditions.

Finally, the parameters of the plan touched upon the removal of sanctions. UN sanctions will be lifted once Iran addresses the commitments it has made in the agreement, the U.S. and EU will suspend sanctions related to the Iran nuclear issue once the IAEA positively recognizes that Iran has delivered on its commitments, and the architecture of U.S. nuclear-related sanctions on Iran will be retained for much of the duration of the deal.