During the first months of the occupation, the Indonesian military faced heavy insurgency resistance in the mountainous interior of the island, but from 1977–1978, the military procured new advanced weaponry from the United States, Israel, and other countries, to destroy Fretilin's framework.
Selama bulan-bulan pertama pendudukan, militer Indonesia menghadapi perlawanan pemberontakan yang berat di pedalaman pegunungan pulau, tetapi dari tahun 1977-1978, militer memperoleh persenjataan canggih baru dari Amerika Serikat, Australia, dan negara-negara lain, untuk menghancurkan basis Fretilin.