Speculation continues to deepen surrounding last Monday’s mysterious explosion at Iran’s Parchin military base, where it is widely believed – including by the UN’s nuclear watchdog (IAEA) – that the Iranians conducted tests relevant to the development of nuclear warheads. Official Iranian outlets had acknowledged early in the week that there had been a fire on a military base somewhere east of Tehran, but opposition sources insisted more specifically that the fire had been generated by an enormous blast and that the military base in question was Parchin.

Before-and-after satellite images published Wednesday by Israeli media outlets all but confirmed the opposition description of the events. They showed what seems to be the aftermath of a massive blast, with one expert telling Israel Defense that “a complete section of structures was simply eliminated by an unexplained explosion.” At least half a dozen buildings were leveled, including some in an area near where the IAEA believes that weapons-related work had taken place.

The New York Times on Thursday published an extensive report on the incident, suggesting that it raised “new questions about whether the blast was an accident or sabotage” and comparing it to a November 2011 explosion at a missile-development site:

The latest explosion, whether accidental or not, comes at a key moment in Iran’s confrontations with the West. It has resisted a series of efforts by the International Atomic Energy Agency to get answers on about a dozen separate issues, of which the activities at Parchin a decade ago were just one, and among the less sensitive. A trip to Tehran earlier this week, just after the explosion, by I.A.E.A. inspectors failed to make progress on that list, though the Iranians said the discussions were “very constructive.” Iran missed a deadline of Aug. 25 to provide a series of answers to the agency.

Fox News reported the same day that the blast – whether it was an accident or deliberately triggered – in any case “cleared up one thing… the nuclear weapons program Tehran has long denied is real.”

The outlet conveyed comments from regional terror analyst Ronen Bergman – also published in Israel’s Yediot Aharonot, where Bergman is a senior political and military analyst – situating the explosion at the center of ongoing debates about the nature of Iran’s nuclear program:

Western officials suspect that at the heart of this secret development is the weapon group developing the nuclear lens mechanism. It’s a complex system of timers and explosives assembled around the core of the bomb, which explode in a way that “pushes” the enriched uranium sphere inwards and starts the chain reaction needed for an atomic explosion.

If the “smoking gun” for the existence of the weapon group is found, it will serve as decisive evidence that Iran has been lying and that there is no point in negotiating with it.

Fox News read the developments alongside Iran’s continued refusal, most recently renewed on Wednesday, to allow IAEA inspectors access to Parchin. The outlet assessed that Tehran’s intransigence on this issue is “a fact that many opponents of the P5+1 talks have long insisted in itself makes a mockery of the so-called negotiation process.”

[Photo: CNN / YouTube]