by Israel of the Osirak reactor. Thereafter, Iraq’s efforts to create a nuclear weapon focused on HEU. HEU can be derived from natural uranium by enriching it in gas centrifuges, which contain rotor tubes spun at high speeds.
After the first Gulf war, inspections by the IAEA revealed that Iraq was closer to the development of a nuclear weapon than either the IAEA or western intelligence had suspected. Following its activities in Iraq in the 1990s, however, the IAEA concluded in October 1997 that:
. . . there were no indications of Iraq having:
produced a nuclear weapon;
produced more than a few grams of weapon-usable nuclear material (HEU or separated plutonium) through its indigenous processes;
otherwise acquired weapons-usable nuclear material; or
retained any physical capability for the production of amounts of weapons- usable nuclear material of any practical significance.
[IAEA Bulletin, 44/2/2002, summarising 5/1997/779]
THE EMERGING INTELLIGENCE PICTURE
In May 2001, the JIC reported:
More recent intelligence indicates efforts by Iraq since 1998 to procure items that could be used in a uranium enrichment programme using centrifuges. These include:
attempts to procure production scale quantities of aluminium pipes of specifications similar to those that can be used for a first generation centrifuge; . . .
[JIC, 10 May 2001]
The intelligence on Iraq’s efforts to procure aluminium tubes was substantial. A series of reports in mid-2001 described the progress of the particular shipment of Chinese-origin tubes that was eventually seized, in part, in Jordan. The seizure did not deter the Iraqis who, if anything, increased their efforts to acquire the tubes from a wider network of potential suppliers and intermediaries around the world. By November 2001, there was intelligence that their requirement had increased to 100,000 tubes.
That Iraq wanted aluminium tubes was therefore never in doubt. Nor was it in doubt that they were made of a proscribed material. But the purpose for which the tubes were sought was not established. We were assured that advice was obtained not only from the Defence Intelligence Staff (DIS) but also from a world expert on nuclear technology who had formerly worked at British Nuclear Fuels Limited. Even so, this did not solve the puzzle. It was clear from an early date that, on the basis of the specifications of the tubes Iraq was seeking to acquire, they would have required substantial re-engineering to make them suitable for gas centrifuge use, including reducing them in length, and machining