The previous chapter described intelligence's effects on its adversaries, but it also has its friends. These produce its own international cooperative system, rather like the other ‘expert’ intergovernmental relationships which develop on the fringes of diplomacy. Cooperation of this kind is a feature of almost all modern intelligence, overlaying the received picture of it as a secretive, exclusively ‘national’ entity. This chapter describes this cooperation and its international effects.

Development of the international dimension

Regular cooperation of this kind is a twentieth-century development but exchanges of some kind have a much longer history. Allies have always shared some information in war, and information exchanges have always been part of diplomacy. In secret intelligence, cipher-breaking had an international dimension in advance of its time. The British liaison with Hanover in the eighteenth century through the royal connection included exchanges of intercepted diplomatic traffic, solutions of ciphers, and decrypted messages; the Hanoverians also trained apprentices to the British organization in the art of forging seals, and may even have supplied the results of collaboration with the Danes.

Yet regular peacetime exchanges did not take place until well after intelligence's nineteenth-century institutionalization. Military staff talks before the First World War required discussion of potential enemy strengths and intentions, and the war subsequently produced organized intelligence cooperation between allies at various levels; by 1916 the British and French intelligence staffs in France were exchanging information daily on German troop movements.