"Time is not on our side in this matter," he stressed during a speech last week at the Park-Hyatt at the Bellevue in an event sponsored by the World Affairs Council of Philadelphia. Looking to current events to bolster his point, the diplomat pointed to a recent proclamation by Iranian President Mahmoud Ahmadinejad that the Islamic republic has the technology and capacity to enrich uranium.
"The announcement is very troubling," he said.
In an ongoing dispute with the West over its right to develop nuclear technology, Iran has claimed that it seeks nuclear power for peaceful means. American and Israeli officials, on the other hand, have claimed repeatedly that the nation's real intent is to stockpile nuclear weapons.
The 15-member U.N. Security Council has set an April 28 deadline for Iran to stop its uranium enrichment program. The United States is pushing for economic sanctions if that date is not met, though Russia and China, which wield veto power over Security Council actions, remain opposed to such measures.
'As Real as It Can Be'
While many experts have predicted that Tehran will gain a nuclear warhead within several years, Bolton warned that the chance exists for an even more immediate atomic threat.
"The nature of the threat posed by Iran is about as real as it can be," he stated, comparing the rhetoric coming out of Iran to that of former Serbian president Slobodan Milosovich, who died earlier this year while awaiting trial on war-crimes charges. "Imagine what it would have been like if Milosovich had [had] nuclear weapons."
On the question of a U.S. military response in Iran - news reports of late have focused on alleged Pentagon plans to strike the country's nuclear facilities by air - Bolton emphatically stressed that Washington is seeking a diplomatic solution.
"It is the intention that there not be armed conflict," he said, adding that the administration has worked for more than three years to resolve the standoff diplomatically through the International Atomic Energy Agency and the Security Council.
But he seemed to suggest that other options, including a military strike, might not be entirely off the table: "I believe the president is very serious when he says it's unacceptable for Iran to have nuclear weapons."
In many respects, Bolton's comments in Philadelphia reflected his reputation for being a tough operator. In his previous position as Undersecretary of State for Arms Control and International Security, he had a well-known propensity to openly criticize the United Nations, and often advocated that the United States take a more unilateral approach to dealing with global threats such as North Korea and Iran.
In opposing Bolton after President George W. Bush nominated him to the U.N. post last year, several critics charged that he misused intelligence data to further his own policy objectives.
Ultimately, the president - whom Bolton served as an attorney in the 2000 Florida recount court battles - bypassed a stalled Senate vote and appointed the man on an interim basis.
True to form, the ambassador did not avoid criticism of the United Nations in his speech, repeatedly asserting that the West's showdown with Iran will test the effectiveness and relevance of the Security Council. As he stated, if the council cannot address the threat of a nuclear Iran, then "you have to ask yourself what utility the Security Council would be in dealing with terrorism and weapons of mass destruction."
During the question-and-answer period, one member of the audience asked the diplomat if America's "aggressive foreign policy" in Iraq and Afghanistan actually encouraged regimes such as Iran to pursue weapons of mass destruction in order to protect themselves. Bolton countered that, if anything, it's been the United States that has been acting out of self-defense.
"Everything we have done has been defensive," he asserted, referring to the overthrow of the Islamist Taliban regime in Afghanistan and the toppling of Iraqi dictator Saddam Hussein. "Our driving force is our effort to bring peace and stability to the world."
Instead of producing further radicalization among Muslim leaders, Bolton pointed out, Hussein's overthrow seemed to convince Libyan dictator Moammar Gadhafi to abandon his own nuclear ambitions.
But all was not centered on the Middle East and Iran at the April 21 lunchtime gathering. At the event's conclusion, Bolton told the 450 people in attendance that he had to rush back to New York for work on a U.N. resolution regarding events in Sudan.
The resolution, expected to be introduced this week, concerns the ongoing genocide in Darfur, which has pitted government-backed Arab militias against the nativist African population. Estimates have blamed the crisis, which began in 2003, for more than 400,000 dead and in excess of 2 million displaced.
The measure, declared Bolton, would be the first step taken by the international community to condemn those responsible for the killings.
"We are not going to wait any longer," he said. "It's been too long already."