February 2, 1979: A. Q. Khan Discusses Centrifuge Cascade in Letter Apparently Later Seized by Canadian Authorities

A. Q. Khan writes a coded letter to his Canada-based associate A. A. Khan about his nuclear weapons research, saying that he is attempting to link together several centrifuges, creating a mini-cascade. This is an important step in building a nuclear weapon, as it is necessary in order to enrich uranium to weapons grade. A. Q. Khan also says that construction work is progressing on a larger facility at his main research site, Kahuta Research Laboratories, and adds that there is “mistrust and apprehension” in the air in Pakistan over the trial of former Prime Minister Zulfikar Ali Bhutto. [Levy and Scott-Clark, 2007, pp. 56] A. A. Khan’s papers will subsequently be seized when he is arrested by the Canadian authorities for assisting the export of nuclear-weapons-related items to Pakistan (see August 29, 1980), and this letter will presumably be among the papers the Canadians obtain.