Iran today buries a senior commander of its missile force, amid claims that the huge explosion that killed him and at least 16 others at a Revolutionary Guard base on Saturday was the work of Israeli agents.

Maj. Gen. Hassan Moghaddam was heralded by fellow commanders as the "founder" of Iran's missile program, which has deployed ballistic missiles with ranges up to 1,500 miles -- enough to reach Europe. The Islamic Revolutionary Guards Corps (IRGC) praised his role in developing artillery and missile units. His importance was such that even Iran's supreme leader Ayatollah Ali Khamanei attended the funeral.

That background would make Moghaddam a prime target in what appears to be a concerted Spy vs. Spy campaign – from assassinations and facility explosions, to three destructive computer viruses, by Iran's count – that have dealt setbacks to Iran's controversial nuclear and ballistic missile programs in recent years. Speculation that Moghaddam was the latest casualty, in the series of strikes that Iran blames on Israel and the US, has been spurred by the fact that such a critical Guard officer was present and killed, during what Iran calls an "accident" involving a routine transfer of munitions.

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"Iran's current missile capability is owed to commander Moghaddam's efforts," Brigadier General Abbas Khani told the official IRNA news agency. "Due to his role ... the enemy always wanted to identify and eliminate him," he said.

Iran has in the past blamed the "Zionist regime" and the US for being secretly behind what it styles a campaign of sabotage. Neither the US nor Israel have ruled out military strikes to prevent Iran acquiring a bomb. Analysts say the death of Moghaddam may be part of a broader, unconventional fight that has been on-going for years.

"Without concluding that this was an assassination, it fits in line with the kind of actions that have...deprived Iran of some of its top influential leadership" in nuclear and missile efforts, says Mark Fitzpatrick of the International Institute for Strategic Studies (IISS) in London. "Missiles are a major component of having a nuclear weapons capability, and this is the first time that we've seen some hint that the missile aspect is bearing the brunt," says Mr. Fitzpatrick, who edited a comprehensive 150-page dossier on Iran's ballistic missiles earlier this year.

The Islamic Republic insists its nuclear program is only to produce energy. Yet the latest report on Iran's efforts by the UN's watchdog International Atomic Energy Agency (IAEA), released last week, found a "systemic" effort by Iran to master weapons-related nuclear work, until it was halted in 2003.

Though some experts question the validity of the IAEA intelligence, the IAEA claimed that some weapons-related work "may" still continue.

Suspicious blast

The blast Saturday, 30 miles west of Tehran, was so large it could be heard and felt in the capital.

As Iran declared it would launch an investigation – and warned that any "foreign hand" would be met with revenge – one Western intelligence source credited Israel's Mossad intelligence service.

"Don't believe the Iranians that it was an accident," the unidentified Western source told Time in a report from Jerusalem. "There are more bullets in the magazine."

The Israeli government has been at the forefront of calls for military action to disrupt Iran's nuclear program. It does not accept the conclusions of a US National Intelligence Estimate (NIE) on Iran in late 2007 – and reportedly reaffirmed earlier this year – that Iran gave up its nuclear weapons work in the autumn of 2003, and has made no subsequent decision to go for a bomb.

The latest NIE report included data from "cutting-edge surveillance techniques," and the results of a six-year effort by US soldiers "working with Iranian intelligence assets," according to a report last June by Seymour Hersh in the New Yorker.

The techniques involved surreptitiously replacing street signs in Tehran with similar looking ones implanted with radiation sensors, "say, near a university suspected of conducting nuclear enrichment," the New Yorker reported.

"American operatives, working undercover," also exchanged bricks from a "building or two" in central Tehran thought to house enrichment activities, "with bricks embedded with radiation-monitoring devices," wrote the New Yorker.

Close to a bomb?

None of those actions, and others described in the magazine, revealed an ongoing nuclear weapons program. The IAEA report largely confirmed that analysis, with the data it spelled out in unprecedented detail last week.

Israeli Prime Minister Benjamin Netanyahu, however, said on Sunday that the IAEA report was limited to information that "can be proven; facts that can be presented in court."

"In practice there are many other things we see, and hence the leading states in the world must decide what do to in order to stop Iran," said Netanyahu. "The efforts thus far did not prevent Iran from progressing towards a bomb, and it is closer to acquiring it, sooner than people think."

Israeli newspapers on Sunday carried reports intimating that the Jewish state was behind the latest blast in Iran and other events going back to a 2007 explosion at another missile base.

A headline in Maariv asked, "Who is responsible for attacks on the Iranian army?" noted Time, over a story that simply listed a half dozen violent setbacks for Iran's nuclear and missile programs.

Other Israeli newspapers listed an October 2010 blast at a Shahab missile facility, the killings on the streets of Tehran of three nuclear scientists in the past two years, and the Stuxnet computer worm that caused a portion of Iran's thousands of spinning centrifuges – which enrich uranium for nuclear fuel, or at higher levels of a nuclear bomb – to operate out of control.

"It hasn't stopped Tehran from acquiring a nuclear weapons capability," says Fitzpatrick of IISS. "Iran is only a political decision away from having a nuclear weapon – a political decision and a certain amount of time."

According to the IAEA report, he says Iran "has already conducted a lot of the weapons development research, and stockpiled enough low-enriched uranium (LEU) for at least two if not four weapons," if enriched further.

Espionage and assassinations

Fitzpatrick said that the Stuxnet malware was "probably overhyped," but "appears to have knocked out 1,000" of Iran's centrifuges, a sizable portion of the roughly 8,000 that Iran has installed. Still, Iran today has more LEU than it did before the virus took hold in Iran's nuclear facilities, and its ballistic missile force can deliver nuclear weapons, even though shrinking them to fit any warhead remains a hurdle.

"I would be very surprised if there were not other efforts in the works" to undermine Iran's progress, adds Fitzpatrick. "So Iran's nuclear weapons community has to be constantly looking over its collective shoulders anticipating further efforts.

"The countries that ... won't abide [a nuclear-armed Iran] don't want to undertake military attack," he says, "so there are a range of other tools they are aggressively employing to try to stop Iran's program without resorting to military attack."

Even among the leadership of the IRGC – which controls Iran's missile program, and has many links, at least, with its nuclear efforts – Moghaddam appears to have had a special place as one of the few favored by Iran's supreme religious leader Ayatollah Khamenei.

"A major part of (our) progress in the field of missile capability and artillery was due to round-the-clock efforts by martyr Moghaddam," Saeed Qasemi, an IRGC commander, told the conservative news website rajanews.com , according to the AP.

"The exalted leader had a special interest in him," said Mr. Qasemi.

A photograph that emerged in Tehran showed a younger Ayatollah Khamenei -- who has made all final state decisions in the Islamic Republic for more than two decades -- holding his left hand to the epaulet of the Guard uniform of the young, bearded Moghaddam.

Iranian officials have complained that their nuclear scientists have been killed on the streets of Tehran – sometimes after their identities and work were disclosed by the UN.

Fereydoon Abbasi, a nuclear scientist who survived an attack a year ago, of a magnetized "sticky bomb" stuck to his car in traffic by a motorcycle-borne assassin, has since recovered and been named the director of the Atomic Energy Organization of Iran.

A colleague, Majid Shahriari, was killed moments earlier on the same day, in a similar attack in another part of Tehran.

Just days after those attacks last December, Iran's top nuclear negotiator, Saeed Jalili, took part in talks with world powers about Iran's nuclear program in Geneva.

With a portrait of Mr. Shahriari beside him at the podium – a strip of black cloth across the upper left corner of the dead scientist – Mr. Jalili said it was "disgraceful" for the UN Security Council that the listing of Iranian scientists for sanctions, he claimed, had led directly to the killing.