By Louis Charbonneau

UNITED NATIONS (Reuters) - An end to a nearly decade-long nuclear standoff between Iran and major world powers will be possible if the United States and its European allies recognize Tehran's right to enrich uranium, a former Iranian negotiator said in an editorial.

"Talks between Iran and the five permanent members of the U.N. Security Council plus Germany (P5+1), scheduled for next month, provide the best opportunity to break the nine-year deadlock over Iran's nuclear program," Hossein Mousavian, Iran's former chief nuclear negotiator, wrote in an editorial in the Boston Globe.

Mousavian, now a visiting scholar at Princeton University in New Jersey, had been seen as a moderate when in the Iranian government. Although he is not currently a policymaker, such public presentations of Iranian thinking is rare.

Iran says its nuclear program is peaceful and rejects U.S. and European allegations that it is secretly amassing the capability to produce atomic weapons. Iran has rejected Security Council demands that it halt enrichment and other sensitive nuclear work, saying it has a sovereign right to atomic energy.

This has led to four rounds of increasingly stringent U.N. Security Council sanctions, mostly focusing on its nuclear and missile industries, but also targeting some financial institutions, a few subsidiaries of its major shipping firm, and companies linked to the Islamic Revolutionary Guard Corps.

In recent months there has been increased speculation about possible Israeli air strikes on Iran's nuclear sites - which some analysts fear could spark a Middle East war.

For the talks, expected to take place in mid-April, to open the door to a resolution of the standoff with Iran, Mousavian said the United States and its European allies must make clear that war and coercion are not the only options.

They should seek enhanced engagement with Tehran, as U.S. President Barack Obama has repeatedly called for.

"This could work - since 2003, Iran has been looking for a viable and durable solution to the diplomatic standoff," wrote Mousavian.

POLITICALLY MOTIVATED CHARGES

Mousavian was Iran's chief nuclear negotiator from 2003 to 2005 before conservative President Mahmoud Ahmadinejad took over from his reformist predecessor Mohammad Khatami. According to Western envoys familiar with Mousavian, he appeared at the time to be genuinely interested in reaching a deal with the West.

After he was removed from the nuclear negotiating team, Mousavian was arrested and briefly jailed in 2007 on accusations of espionage. He was acquitted of that charge, which could have carried the death penalty, but was found guilty of "propaganda against the system."

Analysts and diplomats said the charges against Mousavian were really a reflection of an internal Iranian dispute over how to handle Iran's atomic dispute with the West. Some Iranians favor the moderate line adopted by Mousavian while others have backed Ahmadinejad's more confrontational approach.

Mousavian writes that if a deal that is acceptable to both parties is to be reached, the two sides' "bottom lines" should be identified. Continued...