With such a resounding vote for self-determination, Bougainville has become a visible inspiration for other independence movements in the Pacific, from West Papua, which is seeking to secede from Indonesia, to New Caledonia, which will hold a referendum next year about possibly breaking away from France.

For Bougainville — an area with huge mineral wealth and 250,000 people — the vote also makes it much harder for Papua New Guinea to move slowly through the consultation period required under the 2001 peace agreement that provided a pathway to independence.

“It puts the P.N.G. government in a pretty hard position,” said Jonathan Pryke, director of the Pacific Islands program at the Lowy Institute in Sydney. “If there were to be a smaller majority, say 55 or 65 percent, the P.N.G. government could have found a way to justify really stretching this out and having a period of negotiation that could last years or decades.

“Now with such a phenomenal majority, it’s much harder for them to do that,” he added.

Countries like Australia and New Zealand will also now find themselves squeezed — likely facing pleas for assistance from Bougainville to develop its institutions, and resistance from Papua New Guinea, which has never been eager to give up Bougainville’s bounty.