In November 2005 I wrote a review of the Iranian nuclear danger, recommended powerful global pressure on Iran and said this is not likely, and ended with the following:
“My conclusions are: Iran is determined to possess nuclear weapons and no one can stop them.”
The following two summaries by people of substantial background in this area are important to understand.
Matania

Observations:
Everyone Needs to Worry About Iran - Richard Holbrooke, R. James Woolsey, Dennis B. Ross, and Mark D. Wallace (Wall Street Journal)

• Iran's President Mahmoud Ahmadinejad visits the United Nations in New York this week. Don't expect an honest update from him on his country's nuclear program. Iran is now edging closer to being armed with nuclear weapons, and it continues to develop a ballistic-missile capability.
• The challenge Iran poses is very real and not a partisan matter. We share a common concern - Iran's drive to be a nuclear state. We believe that Iran's desire for nuclear weapons is one of the most urgent issues facing America today, because even the most conservative estimates tell us that they could have nuclear weapons soon.
• A nuclear-armed Iran would pose a direct threat to America's national security. For this reason, Iran's nuclear ambitions demand a response that will compel Iran's leaders to change their behavior and come to understand that they have more to lose than to gain by going nuclear.
• Iran is a deadly and irresponsible world actor, employing terrorist organizations including Hizbullah and Hamas to undermine existing regimes and to foment conflict. Emboldened by the bomb, Iran will become more inclined to sponsor terror, threaten our allies, and support the most deadly elements of the Iraqi insurgency.
• At the same time, Iranian leaders declare that Israel is illegitimate and should not exist. President Ahmadinejad specifically calls for Israel to be "wiped off from the map," while seeking the weapons to do so. Such behavior casts Iran as an international outlier. No one can reasonably suggest that a nuclear-armed Iran will suddenly honor international treaty obligations, acknowledge Israel's right to exist, or cease efforts to undermine the Arab-Israeli peace process.
• Facing such a threat, Americans must put aside their political differences and send a clear and united message that a nuclear armed Iran is unacceptable.
Mr. Holbrooke is a former U.S. ambassador to the United Nations. Mr. Woolsey is a former director of the Central Intelligence Agency. Mr. Ross was a special Middle East coordinator for President Clinton. Mr. Wallace was a representative of the U.S. to the UN for management and reform.

A Wakeup Call on Iran's Nukes - John Bolton (New York Daily News)

• Britain, France and Germany ("the EU-3") have been negotiating with Iran for over five years, and yet Iran has shown no inclination to terminate its nuclear program. The net effect of five years of EU-3 negotiation is that Iran is five years closer to achieving a deliverable nuclear weapon.
• Europe still does not fully appreciate the risks of a nuclear-armed Iran, nor is it willing to take the steps necessary to prevent it. Europe's lack of real concern stems in part from the mindset that it has passed beyond history, and entered a zone of security that will persist as long as outsiders are not "provoked."
• The Security Council will not solve the Iran problem. Russia, and to a lesser extent China, have made it clear that they will block meaningful sanctions in the Council. Russia has an enormous interest in protecting Iran from meaningful Security Council sanctions. Moscow hopes to sell nuclear fuel, and construct many nuclear power plants in addition to the one nearly complete at Bushehr, and sees Iran as a substantial market for high-end conventional weapons sales. Similarly, China's large and growing demands for energy make Iran an attractive partner for assured supplies of oil and natural gas, as well as a potential market.
• On Jan. 20, the new U.S. president will face very unattractive choices if he is serious about disarming this outlaw regime. One is regime change in Tehran, through support of the widespread discontent across Iran with the mullahs. The other is the targeted use of force against Iran's nuclear program. Unfortunately, the only other alternative - Iran with nuclear weapons - is far worse.

The writer, former U.S. Permanent Representative to the United Nations, is a senior fellow at the American Enterprise Institute.