Iran can develop a nuclear weapon within a year and has ready access to enough fissile material to produce up to 50 nuclear weapons, according to a panel of current and former U.S. officials advising the Obama administration.

William Schneider, Jr., chairman of the Defense Science Board and a former under secretary of state in the Reagan administration, offered those estimates Wednesday during a news conference announcing the release of a new "Presidential Task Force" report on Iran by the Washington Institute for Near East Policy.

The report, entitled "Preventing a Cascade of Instability: U.S. Engagement to Check Iranian Nuclear Progress," was signed by a team of policymakers, former officials and Iran scholars that included Sen. Evan Bayh, D-Ind..

Also signing on to the early draft form were two individuals expected to play significant roles in the development of the Obama administration's foreign policy: former Ambassador Dennis Ross, named last month by Secretary of State Hillary Clinton as a special envoy on the Iran issue, and Robert Einhorn, a former assistant secretary of state who is expected to accept a senior position dealing with non-proliferation issues.

The "cascade" refers to a set of 164 high-speed centrifuges used to enrich uranium to the high levels necessary to produce a nuclear weapon. The United Nations' nuclear watchdog, the International Atomic Energy Agency, recently reported that Iran has enough low enriched uranium to produce a nuclear weapon, and currently has 5,600 centrifuges operating at its pilot enrichment facility in Natanz. Iran has declared its intention to add another 45,000 centrifuges over the next five years.

But Schneider said Iran has already "perfected the industrial aspects of enriching uranium," and can easily develop a nuclear weapon long before 2014. 

"The ability to go from low enriched uranium to highly enriched uranium, especially if [the Iranians] expand the number of centrifuges, would be a relatively brief period of time, perhaps a year or so, before they'd be able to produce a nuclear weapon," Schneider said at the news conference. "So it's not a long-distance kind of problem."

Moreover, Schneider warned that the fundamentalist Islamic regime in Tehran -- which has threatened to wipe Israel off the map and equipped and funded regional terrorist groups like Hamas and Hezbollah -- has access to significant amounts of the raw fissile material that would be the core ingredient in such a nuclear arsenal. 

These indigenous natural resources include "yellowcake," the raw uranium ore that is converted to gas and then fed into the cascades of centrifuges. "Iran has enough yellowcake in the country to perhaps produce enough highly enriched uranium, if they go to that length, to produce perhaps fifty nuclear weapons," Schneider said.

Neither of the other two panel members who appeared alongside Schneider at the news conference -- Eugene Habiger, a retried four-star general and former commander in chief of the U.S. Strategic Command, and Nancy Soderberg, a former ambassador to the U.N. and National Security Council staffer during the Clinton administration -- disputed Schneider's claims.

The Washington Instiyute's nine-page report also warned that Israel "may feel compelled" to take military action to try to destroy or retard the Iranian nuclear program if Russia sells the S-300 surface-to-air missile system to Iran. 

"Israeli leaders seem convinced that at least for now, they have a military option," the report states. 

"However, Israelis see the option fading over the next one to two years, not only because of Iran's nuclear progress and dispersion of its program but also because of improved Iranian air defenses, especially the expected delivery of the S-300. ... Israel therefore may feel compelled to act before the option disappears."

Schneider, who along with Habiger and Soderberg conferred with high-level officials from Israel, Jordan, Qatar, and Bahrain during a trip to the Middle East last December, reported that the Israeli military still believes it can hold the Iranian nuclear apparatus "at risk," but will no longer hold that view if Tehran acquires more sophisticated air defense technology from Moscow. 

"It is the transfer of the S-300 that is likely to be a trigger for Israeli action," Schneider said. "The time frame is getting compressed and we need to act quickly if we are going to be successful [in resolving the issue peacefully]."

"Time is not on our side," agreed Habiger. "We've been mucking about on this issue for years now." 

Habiger and Soderberg said it remains possible for the U.S., by working with Russia, China and Arab allies in the Persian Gulf, to persuade Iran not to obtain a nuclear weapon. 

"They are a rational actor," Soderberg said of the Iranian regime. "They are deterrable." If the costs of pursuing the nuclear program are made sufficiently high, the panel said -- particularly through the imposition of sanctions on Iran's oil and gas sector -- Tehran's "cost-benefit analysis" could be changed.

Iran's defense minister visited Moscow last month to press for the Russian state-controlled arms exporter, Rosoboronexport, to sell Iran the S-300 system. Russian officials, at least publicly, were non-committal. 

However, Iran signed a $700 million contract with Russia in 2005 to purchase 29 low-to-medium altitude surface-to-air missiles, which were delivered the following year and became operational in early 2007.

James Rosen joined Fox News Channel (FNC) in 1999. He currently serves as the chief Washington correspondent and hosts the online show "The Foxhole." His latest book is "A Torch Kept Lit: Great Lives of the Twentieth Century" (Crown Forum, October 4, 2016).