The Dutch East Indies had long been a valuable resource to the Netherlands , generating about 14 % of the Dutch national income in the 1930s , and was home to thousands of Dutch people and officials , businessmen and missionaries . By the first half of the twentieth century , new organisations and leadership had developed in the Dutch East Indies . Under its Ethical Policy , the government had helped create an educated Indonesian elite . These profound changes constituted the " Indonesian National Revival " . Increased political activism and Japanese occupation undermining Dutch rule culminated in nationalists proclaiming independence on 17 August 1945 , two days after the surrender of Japan . The Dutch did not plan to let go , for they would be left as merely a minor second-class power ranking with Denmark perhaps . However , the Netherlands was much too weak to reconquer Indonesia . The Japanese had imprisoned all the Dutch residents , and turned the islands over to a native government , which was widely popular . The British military arrived to disarm the Japanese . The Dutch finally returned and attempted to eradicate the Indonesian National Revolution with force , ( sometimes brutal in nature )
brutal
Rawagede massacre
History of the Netherlands