Operation Trikora

Operation Trikora was an Indonesian military operation which aimed to seize and annex the Dutch overseas territory of Netherlands New Guinea in 1961 and 1962. After negotiations, the Netherlands agreed on 15 August 1962 to hand over Western New Guinea to the United Nations.

Background
When the rest of the Dutch East Indies became fully independent as Indonesia in December 1949, the Dutch retained sovereignty over western New Guinea, and took steps to prepare it for independence as a separate country. The Dutch and West Papuan leaders argued that the territory did not belong to Indonesia because the West Papuans were ethnically and geographically different from Indonesians, had always been administrated separately, and that the West Papuans did not want to be under Indonesian control. After its independence until 1961, Indonesia attempted to gain control of Western New Guinea through the United Nations without success. Since the Indonesian National Revolution, Indonesian nationalists had always regarded Western New Guinea as an intrinsic part of the Indonesian state. They also contended that Western New Guinea (Irian Barat) belonged to Indonesia and was being illegally occupied by the Dutch. On 19 December 1961, Indonesia's President Sukarno announced that Indonesia would annex the territory by force.

While the United States, the United Kingdom and Australia sided with the Netherlands' claims to Western New Guinea and were opposed to Indonesian expansionism, they were unwilling to commit military support to the Dutch. The Dutch were unable to find sufficient international support for its New Guinea policy. By contrast, Sukarno was able to muster the support of the Soviet Union and its Warsaw Pact allies, and the Non-Aligned Movement. In response to Indonesian claims, the Dutch were forced to speed up the process of preparing the West Papuans for self-rule from 1959. These measures included the establishment of a legislative New Guinea Council in 1960, hospitals, a shipyard in Manokwari, agricultural research sites, plantations, and the creation of the Papuan Volunteer Corps to defend the territory.

Indonesian military operations
Operation Trikora was to unfold in three phases, infiltration, exploitation and consolidation, all under cover of the Indonesian Air Force. The plan called first for the insertion of small bands Indonesian troops by sea and by air drop who would then draw Dutch forces away from areas where the exploitation phase would stage full scale amphibious landings and paratroops operations to seize key locations. The consolidation phase would then expand Indonesian control over the whole of Western New Guinea.

On 15 January 1962 the infiltration phase of Operation Trikora began with three Indonesian motor torpedo boats were doing a routine patrol around the Aru Sea, south of Western New Guinea. The force was detected by a Dutch Neptune aircraft and one of the torpedo boats was sunk by an intercepting Dutch Navy vessel. Over the next eight months, the Indonesian forces managed to insert 562 troops by sea and 1154 by air drops. The inserted Indonesian troops conducted guerilla operations throughout Western New Guinea from April 1962 onwards, but they were largely militarily ineffective. Over 94 Indonesian soldiers were killed and 73 were wounded during the hostilities. By contrast, the Dutch suffered minimal casualties.

Indonesian military activity continued to increase in the area through mid-1962 in preparation for the second phase of the operation. The Indonesian airforce began to fly missions in the area from bases on surrounding islands and Soviet-supplied Tupolev Tu-16 Badger bombers armed with AS-1 Kennel / KS-1 Komet anti-ship missiles were deployed in anticipation of an attack against the HNLMS Karel Doorman.

By the summer of 1962, the Indonesian military had begun planning a large-scale amphibious and air assault against Western New Guinea. This operation would have been known as Operation Djajawidjaja ("Victory over colonialism") and would have included a substantial task force of 60 ships including several which had been supplied by Sukarno's Soviet and Eastern Bloc allies. On 13 and 14 August 1962, air drops of Indonesian troops were staged from Sorong in the Northwest to Merauke in the Southeast as a diversion for an amphibious assault against the Dutch military base at Biak Island by a force of 7000 paratroops, 4500 Marines and 13 000 Army troops. However, the Royal Netherlands Navy's signals intelligence section Marid 6 Netherlands New Guinea and Dutch patrol aircraft detected the invasion force and alerted their command.

According to Wies Platje, the Royal Netherlands Navy was responsible for the defense of Western New Guinea. In 1962, the Dutch naval presence in New Guinea consisted of five anti-submarine destroyers, two frigates, three submarines, one survey vessel, one supply ship and two Oil tankers. Dutch airpower in Western New Guinea consisted of nine Lockheed Neptune aircraft and 15 Hawker Hunter jet fighters from the Royal Netherlands Air Force. In addition, Dutch ground forces consisted of several anti-aircraft artillery units, five Royal Netherlands Marine Corps companies and three Royal Netherlands Army infantry battalions. As part of the planned defense, the Dutch had considered using Marid 6 NNG to disrupt the Indonesian military's communication systems.

Aftermath
On 15 August, recognising the Indonesians' resolve to take Western New Guinea and not wanting to engage in a protracted conflict involving jungle warfare on the other side of the world, the Dutch government signed the New York Agreement, which handed the colony to an interim United Nations administration. Consequently, Operation Djajawidjaja was called off and Western New Guinea was officially annexed by Indonesia in 1963. The Dutch decision to hand over Western New Guinea to Indonesia had been influenced by its main ally the United States. While the Netherlands was a member of the North Atlantic Treaty Organization and thus an ally of the Americans, the Kennedy Administration was unwilling to antagonize Indonesia since they were trying to court President Sukarno away from the Soviet orbit. However, this proved futile and Indonesia turned its attention to the former British colony of Malaysia, resulting in the Indonesian-Malaysian Confrontation. Ultimately, President Sukarno was overthrown during the Indonesian coup d'etat in 1965 and was replaced by the pro-Western Suharto. In addition, the American mining company Freeport-McMoRan was interested in exploiting Western New Guinea's cooper and gold deposits.

In 1962, the Dutch agreed to contribute US$30 million to the United Nations to fund the development of Western New Guinea. Indonesia also agreed to give the same amount but ultimately did not. The UN however withheld the Dutch funds from the Indonesians when the Indonesian government withdrew from the UN in protest of plans by the UN to send international team to prepare a development plan for West Papua. These funds were restored to Indonesia when it rejoined the UN in 1968.