A PoD somewhere in the 18th century shakes up the balance of power in the East Indies--the Dutch lose some parts of what would have been Indonesia, but gain a piece of western Australia. Time passes; colonialism goes in and out of fashion. Radical ideologies reshape Europe and the rest of the world. Former colonies gain varying degrees of independence. An organization called the International League is formed to prevent the horrors of industrial war from revisiting the world. Over the decades, its mandate evolves until International League troops are being deployed in various troubled parts of the globe far from the centers of power.
One of these is New Guinea, or as the natives call it, Papua--the Disunited Land. Never terribly profitable, various parts of the island kept getting swapped around between the colonial powers, and as a result not much infrastructure ended up getting built. As of forty years ago, New Guinea was still divided between three countries. The Dutch sector was the first to gain independence, as the Republiek van Nieuw-Guinea, followed soon after by former Portuguese Menesesia, which became the República da Menesesia. British Papua was granted independence about five years later as East Papua, just in time to be invaded by the newly unified "Provisional Republic of Papua," consisting of the first two.
While East Papua was eventual overrun and incorporated into the PRP, the Provisional Republic fared poorly--only by sheer numbers had it won the day, and the new country was coming apart at the seams under the stress. Corruption was rampant. Many of the newly-appointed generals were running their territories effectively as independent fiefs, with some going so far as to broker deals with foreign mineral consortiums and arms manufacturers in order to maintain their power. Ethnic violence and sectional conflicts both boiled over, following a coup attempt, and East Papua made a bid to regain its independence.
Currently, the entire island is nominally under the control of the Second Provisional Republic of Papua, but their control barely extends beyond artillery range of the capital. The East Papuan government has regained most of former British Papua, but their independence is still not recognized by much of the world. (With the exception of Australia, which prefers them to the PRP as far as neighbors go, and supports them with the occasional arms shipment.) The remainder of the island is a stew of warlords, Islamic radicals, leftist rebels, and stone-age tribes whose introduction to the wonders of modern technology has been the assault rifle. In recent years, pirates have begun to harass shipping through the region, and the International League has put up a cordon and dispatched peacekeeping forces to occupy several coastal cities in an effort to deal with this problem, but for the foreseeable future, Papua will continue to live up to its name...