The island of New Guinea is split down the middle. The eastern half has been the independent nation of Papua New Guinea since 1975. The western half has been part of Indonesia since 1963, when the United Nations transferred administrative authority from the Netherlands following a controversial process that culminated in the 1969 Act of Free Choice - a vote of 1,025 hand-picked tribal representatives that returned an improbable 100 percent endorsement of Indonesian rule. The line dividing the two halves was drawn by European colonial administrators along the 141st meridian east, cutting through valleys, across ranges, and straight through the territories of peoples whose languages and kinship networks pay no attention to longitude. Roughly 5.6 million people now live in the Indonesian half, the majority indigenous Melanesians whose cultural world extends east into Papua New Guinea and south into the Solomons, not west into Java.

Two geographies divide the region internally. The coastal lowlands are where most of the population lives - the capital Jayapura on the north coast, the port of Sorong on the Bird's Head Peninsula, Merauke in the marshy south, and the Freeport mining town of Timika in the southwest. These coasts have been connected to Indonesian and Southeast Asian trade networks for centuries. Tidore sultans collected tribute here as early as the 17th century, and Srivijaya-era traders reportedly carried sandalwood and bird-of-paradise plumes from this coast to markets in China. The interior is different. The central highlands rise to Puncak Jaya at 4,884 meters, wearing the Carstensz Glacier - one of the last equatorial ice fields on Earth - and cradling valleys where the Dani, Moni, Mee, and dozens of other highland peoples developed agriculture and lived entirely on their own terms until Dutch administrators and missionaries arrived, in many cases within living memory.

More than 250 languages are spoken in Western New Guinea - some estimates run to 300 or more - along with hundreds of dialects. This linguistic density is among the highest anywhere in the world. The languages fall into two broad groups. Papuan languages, unrelated to any other family outside New Guinea, are spoken mostly in the interior and have been evolving in place for tens of thousands of years. Austronesian languages arrived later with seafaring migrants from the west, perhaps 3,000 years ago, and are concentrated along coasts and in Cenderawasih Bay. The Dutch made little effort to impose their language. Indonesian, spoken in schools and government since 1963, is the lingua franca now, but it sits on top of a mosaic of indigenous tongues that linguists are still cataloguing. Several peoples in the interior remain uncontacted by choice.

Lorentz National Park, a UNESCO World Heritage Site, is the largest protected area in Southeast Asia and runs from the southern coast up to the snowy peaks of the central range. Within its boundaries live marsupials that evolved in the same Australian-New Guinean biogeographic world - tree kangaroos, cuscus, long-beaked echidnas, cassowaries. The world's longest lizards, the Papua monitors, hunt here. So do the world's largest butterflies, Queen Alexandra's birdwing and its relatives. Raja Ampat, off the western tip of the Bird's Head Peninsula, is considered by Conservation International to contain the highest marine biodiversity on Earth - over 550 coral species alone, out of roughly 800 described globally. Freshwater and saltwater crocodiles patrol the rivers. The island holds an estimated 16,000 plant species, 124 genera of which are found nowhere else.

The United Liberation Movement for West Papua formed in 2014 to unite independence groups under a single banner. Its chairman, Benny Wenda, declared a provisional government in December 2020. Vanuatu and the Solomon Islands support West Papuan self-determination at the Melanesian Spearhead Group and the Pacific Islands Forum. Indonesia does not. The Indonesian military has maintained a heavy presence since 1963, and sporadic violence between the Free Papua Movement and security forces continues in the highlands. Indonesia has invested heavily in infrastructure - the Trans-Papua Highway has been pushing road access into regions that never had it - and in economic integration through transmigration programs and new airports. Whether this amounts to development or displacement depends on whom you ask. The arguments over names are arguments over what happened here and what should happen next.