At midnight on 30 June 1997, Britain will end its century and a half of colonial rule in Hong Kong, leaving China to resume sovereignty over the fabulously wealthy city-state and its six million people. The terms of the handover are to be those set down in the Joint Declaration on the Question of Hong Kong, initiated by Britain and China in September 1984 after two years of intense and secret negotiation. A treaty unparallelled in peacetime, the Joint...