The BBC's security correspondent, Frank Gardner, can reveal that Arab soldiers have been taking part in dangerous missions alongside US troops in Afghanistan.
Troops from the United Arab Emirates (UAE) have been delivering humanitarian aid to their fellow Muslims and, on occasion, fighting their way out of Taleban ambushes. Though Jordanian forces have been carrying out some base security duties, the UAE's troops are the only Arab soldiers undertaking full-scale operations in the country.
Until now, their deployment has been kept so secret that not even their own countrymen knew they were here.
In a windowless room, surrounded by sandbags, the Emirati patrol commander briefs his troops for tomorrow's mission: a hearts-and-minds visit to an Afghan village.
His troops are dressed in desert fatigues, topped with sand-coloured shemaghs, the traditional wrap-around headdress of the Gulf.
When the patrol moves out through the mountain valleys, it looks exactly like any other convoy from the US-led coalition.
The Emiratis are on their guard, wary of ambush, alert for roadside bombs.
At the last minute, the village they had originally planned to visit was deemed too dangerous: the Americans could not guarantee to provide air cover.
So they travel instead to one they have been to before, to hand out gifts and discuss what projects need building.
As fellow Muslims, they get a warm reception from the villagers.
"At first I thought these were American soldiers and I wanted them to leave but when they said they were Muslims I knew they were our brothers," a young Afghan man says.
Hajji Fazlullah, another Afghan villager, says: "The Arab troops come in our country and our village, we are very happy."
Of course, these are not the only coalition troops giving out aid to Afghans. But what is really winning hearts and minds is the Islamic connection.
The Arabs use a shared Islamic faith to bond with the Afghans
In a sunlit courtyard, a small boy recites the Koran from memory, watched by his proud father, and by the UAE's Maj Ghanem Al-Mazroui.
Unlike most western military officers, he has spent over two years getting to know these villagers, eating and praying with them.
But handing out humanitarian aid in Afghanistan is not as easy as it sounds.
As the crowd builds up rumour spreads that there is not enough to go round and people surge forward.
The Afghan police wade in, pushing and hitting the villagers.
More than once, Maj Ghanem has to restrain them. Without sensitive handling, the situation could easily descend into a riot.
There is even a scramble for the empty cardboard boxes.
But eventually the Arab troops manage to restore order and they leave without a shot being fired.
'Here to help'
Still, it is going to come as a surprise to most people that for the last five years, an Arab Muslim army has been operating here in Afghanistan, alongside the Americans as part of the coalition.
Afghans seem to respond well to UAE troops efforts' to help them
So I asked Maj Ghanem whether he was worried about how some people in the Arab world might react to this.
"We have an answer for that. Even if you are asking back in the UAE or in the Gulf, or you asking here, we have the same answer," he said.
"We make a contract with the US Army to help the people down here, not to fight".
But I put it to him that in fact his troops have been fighting insurgents as well as handing out aid.
"If we have any types of personal attacks we react with fire. And after that we go to the elders in this area: 'Why are you shooting us? We came here to help you.
"'If you have the same picture of all coalition forces, we are different. We came here to help you.'
"And we try to convince the people about the US, about British. They came here to give you peace."
Blueprint for Afghanistan
The man who kick-started the Arab humanitarian effort in Afghanistan five years ago is Hamad al-Shamsi, the UAE's humanitarian aid co-ordinator.
A devout Muslim, a father of 10, and a former fighter pilot, he has been travelling all over Afghanistan, often at great personal risk.
The UAE troops in convoy look much like the other coalition forces
He believes his country's efforts are smoothing a path for the rest of the coalition.
"If we are visiting [somewhere] like this village and we do some service for them, then the coalition will know when they are approaching that there is somebody from their side who is coming here who has done something for us," Mr Shamsi says.
"So the relations will be easier than if they come directly with no first approach".
His words are born out by some of the Afghans we meet, including Governor Merajudeen Patan, who was instrumental in getting UAE's money invested in the troubled province of Khost.
"People are not afraid that Emiratis will harm their religion, or disrespect the mosque or burn the mosque, things of this nature," Governor Patan says.
"People are very friendly with them. Everybody will drag them in for lunch or for dinner."
These are hearts-and-minds operations at their most effective - drinking tea with Afghans, discussing what help can be provided.
The Emirati approach is to meet their fellow Muslims' religious needs first, then build schools and clinics later.
But for this to have a wider, lasting, and national effect, the blueprint would need to be repeated and expanded by others, many times over and throughout Afghanistan.
And that is not likely to happen in the near future.