After the end of World War II, on 17 August 1945 Indonesia proclaimed its independence; Moestopo maintained control of the nascent military forces in Surabaya and forcibly disarmed the Japanese forces while armed with bamboo spears. In October of that year he declared himself interim Minister of Defence. On 25 October of that year, the 49th Indian Infantry Brigade under the command of Brigadier Aubertin Walter Sothern Mallaby, arrived in the city; Mallaby sent his intelligence officer Captain Macdonald to meet with Moestopo. According to Macdonald's report, Moestopo was opposed to the arrival of British forces.