U.S. President Donald Trump's surprise backing of Morocco's claim to sovereignty over disputed Western Sahara upended years of international consensus, but will this break a deadlock or inflame a conflict?
This article looks at how a dispute often dubbed a "forgotten war" suddenly shot to world attention - and what it means for the region.
For nearly three decades there was an uneasy but stable status quo in Western Sahara.
The former Spanish colony, home to less than a million people, has valuable resources including fish-rich Atlantic waters, phosphates, potential oil reserves and, for Rabat, a strategic road south to lucrative West African markets.
Morocco controls three-quarters of the Britain-sized desert region, offering it autonomy but insisting it has sovereignty. It has poured in investment, and several nations have opened consulates there.
The rest, behind a 2,700-kilometre (1,700-mile) sand barrier, is run by the Polisario Front, an Algerian-backed pro-independence group demanding a promised United Nations-run referendum.
However, the UN-backed political process is stalled, with the UN envoy post vacant for over a year.
Last month, a 1991 ceasefire collapsed after Morocco sent troops into a UN-patrolled buffer zone to reopen the road to Mauritania, blocked by a group of separatists.
The Polisario has since claimed repeated exchanges of fire, although details are murky in a region largely off limits to journalists.
Then on December 10, the U.S. took the unprecedented move of formally recognizing Morocco's claims to Western Sahara, a quid pro quo deal for Rabat announcing it was "resuming" diplomatic ties with Israel.
Rabat hailed the U.S. announcement as a "historic breakthrough", saying it is the guarantor of stability in the region.
Polisario responded angrily. A top official said Trump's declaration "violated... the decisions and resolutions of all international bodies."
The UN - which deploys over 400 personnel in its UN Mission for the Referendum in Western Sahara - said its position is "unchanged".
"Recognition will not simplify the territory's complicated status, as it is still designated by the UN as a 'non-self-governing territory'," Verisk Maplecroft risk consultancy analyst Hamish Kinnear said.
Since Trump's comments, Secretary of State Mike Pompeo has also said the U.S. still favored a diplomatic resolution.
Few key nations are expected to change their position.
UN Security Council member Russia swiftly denounced Trump's move, while France, Morocco's former colonial ruler, said it was committed to "a political solution".
Morocco's military dwarfs the Polisario, but the latter does have the powerful backing of Algeria, Rabat's regional rival.
The Polisario has vowed to press on with its fight "until the total withdrawal" of Moroccan troops.
"The announcements will make a bad situation worse," Kinnear added. "Morocco, emboldened by what is clearly a U.S. endorsement, will feel free to pursue its war effort against the Polisario Front, which may appeal for the intervention of Algeria, its main foreign backer."
For the Polisario, the U.S. move was a "significant setback", said International Crisis Group (ICG) expert Riccardo Fabiani.
"With their faith in the peace process already at an all-time low, Polisario forces could see the move as further justification for resuming hostilities... and might trigger an escalation," Fabiani said.
Whether that happens depends largely on Algeria, where the Polisario operates rear-bases and runs camps for tens of thousands of Sahrawi refugees.
"Algeria is strong," Algerian President Abdelmadjid Tebboune has warned, with his prime minister pointing to "foreign manoeuvres" that aimed to destabilise the country.
Western Sahara borders regions where a disparate Islamist insurgency has taken root in recent years.
"Instability in the region is fuel to extremists," said Abdy Yeganeh, a former British diplomat now working for Independent Diplomat, a non-profit group supporting peace efforts.
Western Sahara is also a jumping off point for migrants from sub-Saharan Africa, who risk the dangerous sea crossing to Europe, especially to Spain's Canary Islands.
"Resolving the Western Sahara conflict should matter for Europe," Yeganeh added.
The African Union has urged all sides to sit at "the negotiating table".
But Western Sahara poses a thorny challenge for the bloc, with both Morocco and the Polisario-declared Sahrawi Arab Democratic Republic (SADR) as members.
So any negotiations will likely be driven by the U.S. and UN.
However, critics are gloomy about the prospects for swift action by the UN, with the Security Council split on key issues.
"This is one of those sad cases where the UN is very unlikely to solve the conflict, but its presence may help keep it from escalating again," the ICG's Richard Gowan said.
For U.S. President-elect Joe Biden, Western Sahara will be far down the list of problems he faces.
But he may find it hard to reverse Trump's announcement, since that could jeopardize Morocco's commitment to the Israel deal.
For Yeganeh, the first practical step should be the appointment of a dedicated UN envoy.
"What is clear is the need for a political solution," Yeganeh said.