Internal Security in the British Empire to 1945
Before the Second World War, Britain's military, colonial police and administrators, its intelligence services, civil servants, diplomats and statesmen, accumulated a body of IS lore about the threats that they faced, from riots to 'insurrection'. Their ability to identify, assimilate and disseminate 'lessons' in the light of experience depended on whether they felt that existing wisdom needed revision, on the existence of machinery to effect change, and the readiness of others to accept it. Insurgency, pioneered by the Irish (1919-21) and the Palestinian Arabs (1937-39), was an unusual form of conflict and so would not transform IS thinking and practice overnight. But, after 1900, along with growing numbers of modern guerrillas, there was 'a qualitative change in the nature of [some] ... opposition', 1 which could offer valuable insights to counterinsurgents.