The Netherlands kept possession of West New Guinea . War threatened , but the United States under President John F. Kennedy negotiated a settlement . Regardless of the wishes of the local inhabitants , West New Guinea became part of Indonesia . After Kennedy 's death , President Lyndon Johnson escalated the war in Vietnam , which greatly heightened tensions with Indonesia in 1964 – 65 . By mid-1965 , Sukarno was edging closer to China . He denounced American imperialism , and inspired anti-American demonstrations . War was threatening . Unexpectedly , and without American help , the Indonesian army overthrew Sukarno and ended his anti-American regime . Many thousands of Communists were killed across Indonesia . The hostility ended and the United States started providing financial In military aid to Indonesia
were killed
Indonesian mass killings of 1965–66
Indonesia–United States relations