The anniversary is hardly on many minds, but that is only to be expected. For the event it commemorates sparked what it is still, 30 years on, the world's most forgotten conflict.Even in its heyday in the 1980s few people paid attention to the war in the Western Sahara, one of the most inhospitable places on the planet. But the Sahrawi people and their supporters have this week been remembering November 1975, when King Hassan of Morocco launched his famous Green March to occupy the gravel desert that had been evacuated by Spain after nearly a century - effectively decolonising it out of existence.
King Hassan invoked centuries-old ties of allegiance by Saharan tribes to assert his sovereignty and claim the territory's rich phosphate deposits and offshore fishing grounds.
He called it "legitimate blackmail" when he organised the march - 350,000 people in trucks, buses and on foot - immediately after the International Court of Justice at The Hague ruled in favour of self-determination for the Western Sahara.
Instead, the king's nationalist flourish triggered a 16-year war. Neighbouring Algeria - bastion of anti-colonialism, non-alignment and third world solidarity, forged in its own conflict with France - backed the Sahrawis, whose lightly-armed Polisario guerrillas fought the Moroccan army to a stalemate and a UN-brokered ceasefire in 1991.
The Polisario Front was set up in the early 1970s by young Sahrawis who had studied at Moroccan universities and were inspired by the backing of the UN - it had included the Sahara on a list of countries to be decolonised and recognised the right of the Sahrawis to self-determination - and by that other unequal struggle, of the Palestinians against Israel.
In 1976 Polisario unilaterally proclaimed a Saharan Arab Democratic Republic (SADR), complete with a flag, ministers and ambassadors. That made significant diplomatic gains, especially in Africa. But it remains a phantom state without a territory to control.
The disputed desert is the size of Britain, with a population of 260,000 Sahrawis and Moroccan settlers. But some 150,000 refugees, including those who fled the 1975 invasion and their descendants, remain to this day in grim refugee camps at Tindouf in south-west Algeria.
Since the 1991 ceasefire, hopes for a negotiated solution have been stuck on disagreements about the modalities of a proposed UN-backed referendum on the future of the territory.
In 2003 a UN plan proposed to give the Sahara autonomy under Moroccan sovereignty pending a referendum, a position which Polisario reluctantly accepted even though it fell far short of its demand for full independence. Morocco rejected the plan.
Intense haggling over precisely who is eligible to vote underlines the view that Morocco cannot risk a free vote it knows it would lose.
King Mohammed, who succeeded his father in 1999, has successfully played for time, arguing that any partition would lead to the "Balkanisation of the whole Maghreb region." His twin assumptions - that Polisario is in no position to resume attacks against Morocco, and that the issue will never be given a high priority internationally - are probably correct.
The Western Sahara used to be bracketed together with the parallel case of East Timor, annexed by its powerful neighbour Indonesia after the Portuguese left, also in 1975. But when the Timorese finally won their independence in 1999, the Western Sahara was left as the world's last significant colony.
Inside the territory, demonstrations calling for self-determination are regularly put down by the Moroccan authorities. Media access is limited and strictly controlled, and Amnesty International reports often on the mistreatment of political prisoners, some using hunger strikes to attract publicity. Hundreds of Sahrawis remain unaccounted for or "disappeared".
Last week a Sahrawi named Lembarki Hamdi was killed by Moroccan police after a demonstration in the capital, El Aaiun, behind the 1,200-mile long sand wall, fortified by trenches and barbed wire, that separates the Moroccan-controlled zone from a corridor controlled by Polisario.
Seeking to overcome indifference and ignorance of the issue is a small but energetic pro-Sahrawi lobby, which has focused recently on attempts by the EU to sign an agreement with Morocco that would allow European fishing vessels to exploit Sahrawi waters. Oil companies considering investing in the area have been warned they could face attacks.
International attention paid to the Sahara is extremely slight and sporadic, intensifying only when the UN security council extends the mandate of its mission, Minurso, which was originally tasked with preparing that elusive referendum. The mandate was extended for another six months at the end of October and will doubtless be renewed again at the end of next April. But there is no sign of any breakthrough.
Earlier this year Peter van Walsum, a Dutch diplomat, succeeded the former US secretary of state, James Baker, as Kofi Annan's special envoy to the Western Sahara. Baker resigned after trying in vain for seven years to resolve the conflict, remarking caustically that the Sahara was not Kuwait and thus not important enough to generate the necessary political will.
In addition, Morocco, which has its own Islamists to deal with, is a staunch friend both of the US - especially in the global war on terror - and a Europe concerned about maintaining stability and controlling immigration on its southern flank. The Sahrawis cannot hope to muster such clout.
So, three decades after King Hassan's Green March it is hard to see any way out of the impasse. The worry is that failure to settle the dispute will encourage Muslim fundamentalists, who have so far been absent from the Sahrawi refugee camps.
"It is rumoured that John Bolton, new US representative to the UN, is impatient to see progress in the matter," the Western Sahara Solidarity Campaign commented in an anniversary statement that smacked of wishful thinking. "Perhaps his muscle and prior experience with James Baker will lead to UN resolutions being implemented at last?"
No one is holding their breath.