The disclosure by the Dutch authorities this week that they intercepted a consignment of chemical compounds bound for Sudan last April appears to lend some credence to Washington's justification for attacking Sudan with cruise missiles on 20 August.
The United States claims that traces of Empta, a chemical compound used to manufacture the lethal nerve gas VX, were found at the plant it bombed in Khartoum.
Diplomats and experts continue to challenge assurances by the US that the Shifa Pharmaceuticals factory destroyed by five cruise missiles was making not only antibiotics and malaria drugs but also the precursors to VX, the deadly poison that Saddam Hussein is believed to to be stockpiling.
The Dutch revelation corroborates the US claim that Sudan was under surveillance for many months before the attack as part of a covert operation, and strengthens the theory that the Americans picked the wrong factory but the right country.
In an effort to dispel mounting international scepticism, US officials said this week that the spying operation against Sudan helped to establish definitively that the Shifa Pharmaceuticals Industries factory was linked to Iraq's chemical weapons programme. An agent of the Central Intelligence Agency had gained access to the area around the plant, where he scooped up soil and returned it to the US for analysis at a private laboratory.
A chemical weapons expert in the Dutch national defence research institute said there was no doubt about Sudan's involvement in a chemical warfare programme. But he expressed serious doubts about the credibility of the US tests on the Shifa plant, saying: "US intelligence is not always satisfactory. The way the sample was taken and analysed gives us grounds for doubt."
The economics ministry in The Hague is believed to have acted on information filtered from the CIA through the BVD, the Dutch intelligence agency, earlier this year when it rejected an application from a Dutch exporter for a licence to ship chemicals to Sudan for the manufacture of agricultural fertilisers.
Despite demands from the Dutch parliament for a full explanation of its action, the government has so far refused to name the chemical compounds, the companies involved in the transaction or its reason for stopping the shipment.
"We had leads which suggested that these raw materials were going to be used for non-peaceful means," a foreign ministry spokesman said.
It was Sudan's presence on an unofficial blacklist operated by an informal association of 31 governments known as the Australia Group, set up after the Iran-Iraq war, that allowed the Dutch to take action. The group is believed to rely heavily on US satellites and spy network for information.
Australia Group members demand that importers in blacklisted countries prove beyond any doubt that they are not using the chemicals they want for the production of weapons.