The United States and Britain undertook a secret campaign in the late 1970s to prevent Pakistan from going nuclear. The newly declassified State Department Cables, released by the National Security Archive say the two countries also unsuccessfully tried to block Pakistan's attempted covert purchasing of gray area technology for its atomic weapons programme. The declassified documents also indicate that the US issued 300 demarches to Nuclear Exporters during 1978-1981 in attempt to halt Pakistani nuclear purchases.At the same time, both Britain and the US kept India in the dark, even as Indian officials had better intelligence information about Pakistan's nuclear weapons programme.The National Security Archive said the documents, however, do not mention the name A Q Khan.