The break for American intelligence operatives tracking Abdul Qadeer Khan’s nuclear network came in the wet August heat in Malaysia, as five giant cargo containers full of specialized centrifuge parts were loaded into one of the nondescript vessels that ply the Straits of Malacca. The C.I.A. had penetrated the factory of Scomi Precision Engineering, where one of the nuclear network’s operatives — known to the workers only as Tinner — watched over the production of the delicate machinery needed to enrich uranium for nuclear bombs. Spy satellites tracked the shipment as it wended its way to Dubai, where it was relabeled “used machinery” and transferred to a German-owned ship, the BBC China. When it headed through the Suez Canal, bound for Libya, the order went out from Washington to have it seized, according to accounts from American officials. That seizure led to the unraveling of a trading network that sent bomb-making designs and equipment to at least three countries — Iran, North Korea and Libya — and has laid bare the limits of international controls on nuclear proliferation. Full Story