IN AUGUST 1991, in the aftermath of the Gulf War, United Nations inspectors in the north Iraqi town of Jabe Hamrayn shaded their eyes from the desert sun and peered in astonishment up the steep hill before them.
Soaring nearly 62 metres was a giant gun barrel held in place by a steel framework embedded in concrete blocks. Here at last, they thought, was confirmation of Project Babylon, Saddam Hussein's plan to confound his enemies by building the biggest gun in the world.
Eighteen months earlier, on March 22, 1990, Dr Gerald Bull had stepped out of the lift in his luxury Brussels apartment block and turned towards his front door.
As the 62-year-old Canadian-born ballistics scientist reached for his key, a professional killer using a silenced 7.65mm pistol shot him five times at point-blank range.
The following month, at a port in northeast England, British customs officers raided the Bermuda-registered ship MV Gur Mariner and seized eight steel tubes packed in wooden crates.
Although the crates were labelled ''Ministry for Industries and Minerals, Petrochemical Project, Baghdad, Iraq'', the investigators said the tubes were part of a gun ''capable of firing a nuclear shell that could easily hit Iran''.
Two weeks later in the English city of Sheffield, customs officers arrested Dr Christopher Cowley, a British metallurgist and an associate of Bull, and charged him with attempting to export the tubes, contrary to laws banning the export of arms to Iraq. It was the UN's discovery of the giant gun at Jabe Hamrayn that brought these disparate events together and the British media, after official briefings, rushed to explain what was behind ''the Iraqi supergun''.