'Welcome to the Bad Boys House' is etched into the sand berm with white rocks and goats' skulls. Behind it sits a squat complex of tents and portacabins. Tracks in the sand mark the "roads": roads to nowhere, tracks petering out into the desert. A brief stop, then back in the helicopter, a battered Russian MI-8 with "UN" in large black letters on the side. Below, the Sahara is turned, briefly and incongruously, into a flood plain, as the first rains of the season arrive.

We land in front of Conor Burke's home, a near-identical camp, without the rock'n'roll motto. This is Tifariti Team Site, one of nine peacekeepers' bases in Western Sahara, and Lt Col Conor Burke, born in Kildare and based at Collins Barracks, Cork, is in charge. He has 12 men under him, from 12 different countries.

"We look out for each other," he says. "The bottom line is respecting others."

He has been here for four months of a six-month posting. "Time flies for me here. I'm busy. There are patrols to be preparing for, reports to do, cleaning, meeting people, whatever. At 1830, we play volleyball for an hour, and that passes the evening. Time goes quickly but we don't dwell on it."

A few hundred metres across the desert is the village of Tifariti, bombed out during the war and hesitantly being rebuilt. There are no roads, no signage, no traffic, no people. In a tiny, dark shop, a wizened Saharawi man in military fatigues and a traditional headdress awaits rare customers. There are some tents scattered in the bush around.

"You adapt," says Burke, grinning. "In Kildare, it's very flat and level, and you can travel for miles without seeing a tree. That helped me quite a lot."

This is a classical UN peacekeeping mission. Two hundred and thirty Blue Berets, three Irishmen amongst them, patrol the desert, visit military installations on both sides, and report violations of the peace accord. These tend to be minor: the situation is "calm and stable", says Burke, and the peacekeepers are unarmed.

For Julian Harston, the veteran British ex-diplomat who runs the UN mission here, the peacekeeping "has been a great success".

"There's not been one shot fired in anger between the sides since the ceasefire was put in place."

That, though, was 17 years ago. The UN came in to help organise a referendum on self-determination. The referendum never happened. Currently, the two sides are talking about having talks about it. In the meantime, a second generation of Saharawis has been born into life in the refugee camps, or is being radicalised by human rights abuses, and political impotence, in the Moroccan-controlled territory.

These, though, are none of Julian Harston's business. "I don't have either a mandate or the means to monitor human rights." His mandate comes from the Security Council, where permanent member France, the former colonial power in Morocco and now a key ally, fights to keep human rights off the Western Saharan agenda.

This is the nature of international realpolitik, and Harston argues that the UN "machine" should not be blamed.

"I don't think the United Nations has failed Western Sahara. We've done precisely and exactly what we were asked to do by the Security Council. We've maintained a ceasefire here
and we have continued to create a space for the parties to negotiate a settlement."

Meanwhile, Conor Burke and his men drive their regular routes through the desert, stopping to talk to the occasional nomad, keeping friendly contact with their military counterparts, watching, recording, reporting.

It is good work, even if it is not enough. But is it ever?