The photographs did the most damage. They showed the complex at various stages of construction since 2002. The main building looked like a tree-house on stilts, with pipes leading into a pumping station on the banks of the Euphrates. It was going to need a lot of water to create fissile material. As the building grew, it sprouted concrete piers and roofs, which could only have one function – to camouflage the place from above. Al-Kibar's core design, they could now prove, was the same as North Korea's Yongbyon reactor, even down to the number of holes for fuel rods.

The clincher was a photo that showed an Asian guy in blue tracksuit trousers standing next to one of the Arabs who'd been working there all the time. The Brits quickly identified the Asian as Chon Chibu. He was the chief engineer behind the North Koreans' plutonium reactor at Yongbyon.

The Israelis were wetting themselves with this int, but it still wasn't enough for the US. Washington thought it would be years before the Syrians were capable of producing a bomb. They could be fucked up without the US getting drawn into another war.

Things might have stayed that way had not a high-ranking Iranian decided to switch sides. General Ali-Reza Asgari was a massive catch. Head of Iran's Revolutionary Guard in Lebanon in the eighties, he'd become Iran's deputy defence minister in the mid-nineties. His fall from grace had come after the election victory of hardliner Mahmoud Ahmadinejad in 2005. Asgari had branded several of those close to the new president as corrupt. He was living on borrowed time.

The Iranian general was an intelligence goldmine. He confirmed that Tehran was building a second, secret, plant in addition to the uranium enrichment plant in Natanz, already known to the West. And that Iran was funding a top-secret nuclear project in Syria, launched in co-operation with the North Koreans.