World War II, on the other hand, brought unparalleled social and political upheaval to Penang. In early December 1941, Japanese warplanes indiscriminately strafed and bombed George Town, and wiped out the defending Allied air squadrons. While the British Army had earlier designated Penang Island as a fortress, Lieutenant-General Arthur Percival then ordered a withdrawal from Penang. Not only did the British abandon the Batu Maung Fort south of the city, they also covertly evacuated Penang's European population, leaving the rest of the populace to their fates. Some historians have argued that the withdrawal and the silent evacuation of the European population led to the loss of the British sense of invincibility, and that the collapse of British rule in Southeast Asia came not in Singapore, but in Penang.