forces. The Vichy government also conducted an effective propaganda campaign within France, encouraging the people to fight the "hereditary enemy" (Britain) and equating the defence of Syria as a matter of national honour. As a result of the unexpected resistance British forces quickly required reinforcements, which could only be provided piecemeal. Many of the British and Commonwealth troops were novices and the hot, dry, mountainous terrain was a severe test, in which Indian Army units excelled. The Australian contingent had to cope with the worst country but conducted the most effective attack, "with a good plan carried through with great determination". The achievement of air superiority was delayed by the lack of aircraft but the urgency of the situation made it impossible for the naval and ground forces to wait. Vichy French airmen concentrated their attacks on ships and ground targets, which were highly effective until they were forced to move north. The scare caused by the German success in Crete had been exaggerated because the German parachute and glider invasions of The Netherlands and Crete had been very costly and there was little chance of the Germans gaining a bridgehead in Syria. The Germans withdrew from Syria to preserve their forces and to deprive the British of a pretext for invasion. The British invaded Syria anyway and gained naval and air bases far north of Suez, thus increasing the security of the oil route from Basra to Baghdad in Iraq to Haifa in Palestine. Casualties In August, the Vichy authorities announced of whom had been killed, missing, and had been taken prisoner. After the war, Dentz stated that had been killed, which would mean and against a British claim of of all natures. The Vichy Air Force lost most destroyed on the ground, the navy lost one submarine and defected to the Free French. The armistice agreement led to the repatriation to France of and civilian personnel in eight convoys, consisting of three hospital ships and a "gleaner" ship, from 7 August to 27 September. Prisoners taken by the Vichy French forces were returned but several British prisoners of war had been sent out of Syria, some after the armistice. The delay in obtaining the return of these prisoners led to the detention of Dentz and officers in Palestine who were released when the British prisoners were returned to Syria. British and Commonwealth casualties were the Australians suffered killed