Iran's President Hassan Rouhani tells NPR that much like in the United States, there are in his country "two differing viewpoints" on the six-party nuclear deal — one that is cautiously optimistic of success and another that is highly skeptical of Washington's desire to live up to its end of the bargain.

Iran is hailing the International Atomic Energy Agency's visit to a controversial military base, saying it disproves "fictions" about the site's nuclear capabilities. But critics note that samples were taken by Iranian officials, without inspectors being present.

NPR's Peter Kenyon reports:

"The head of the IAEA and his top nuclear safeguards official visited the Parchin military base, long a target of suspicions involving possible military dimensions to Iran's nuclear program. Tehran insists its program has always been peaceful.

Security professionals in both the U.S. government and in private industry have long feared the prospect of a cyberwar with China or Russia, two states capable of launching destructive attacks on the computer networks that control critical assets such as the power grid or the financial system.

Now they face a new cyberthreat: Iran.

"[The Iranians] have all the resources and the capabilities necessary to be a major player in terms of cyberwarfare," says Jeffrey Carr, an expert on cyberconflict who has consulted for the U.S. Department of Defense.