 When Germans invaded Yugoslavia they met in the Chetniks an organization trained and adapted for guerilla warfare.Although there were some clashes between the Germans and the Chetniks as early as May 1941, Mihailović thought of resistance in terms of setting up an organisation which, when the time was ripe, would rise against the occupying forces.British policy with regard to European resistance movements was to restrain them from activities which would lead to their premature destruction, and this policy coincided initially with the concepts on the basis of which Mihailović's movement was being operated.