Noriega hasn’t got a smoking gun, but his circumstantial evidence is intriguing. Much of it concerns three Iranian facilities that have been located in Venezuela’s remote Roraima basin, south of the Orinoco River. One is purportedly a concrete plant; one a tractor factory; and one a gold mine. Noriega says that all three are protected by no-fly zones and that the tractor factory contains a high-security compound guarded by Iranians. The factory has produced only a handful of tractors, and there is little evidence of concrete production or gold mining at the other sites. In December 2008, Turkey intercepted 22 containers from Iran bound for the tractor plant; they contained nitric acid and sulfate, which are used in making explosives.

According to surveys by Western companies, all of the Iranian installations lie in a region that contains extensive but unexploited reserves of uranium. Citing what he says is a source at the highest level of Chávez’s government, Noriega alleges that Iran is using the three facilities as a cover for the clandestine mining and export of uranium ore — which it needs to continue fueling its growing number of nuclear centrifuges. Noriega says the ore can be shipped up the Orinoco to platforms off the Venezuelan coast, where it can be picked up by ships without the need for port registration.