They had just been brought off al-Faw peninsula by K Company, Fire Support Group, 42 Commando Royal Marines, and were waiting to be taken to a vast tented PoW camp close to the port of Umm Qasr.

It was hard to spot a single fit-looking male among the Iraqis as they sat in various stages of physical and mental ruin on a hillside overlooking the Shatt al-Arab waterway.

The only sounds were the gruff entreaties of a commando, bayonet fixed to his assault rifle, as he urged his charges to drink more water, or the lilting groans of men too afraid even to express their pain at full cry.

Although I was not permitted to speak to the prisoners, it was not hard to read their minds. They looked as if they had passed through some awful torment which, having endured and survived, they dared not believe was over: dumb relief that their war, on only its fourth day, was at an end.

The sickliest had been put at the rear of the column. There was a man in a torn green tunic with a chest wound and a field medical assessment already pinned to his clothes. His hair was almost white and he looked at least 50 years old. The prisoner had a heart condition and had passed out several times, so he was being monitored by “Bootnecks” (Marines) who had themselves been fighting for four days.

It was a surreal tableau; six heavily armed commandos passing ceaselessly among their ragtag captives, distributing bottles of water, checking their eyes, their pulses, but pushing their heads down to the floor if any attempted to look around or talk to his comrades. Kill or cure — it was just an expression one hears until you have seen Royal Marines guarding their prisoners.

Captain Jamie Norman, 25, explained the dilemma. “We want to maintain them in battle shock until they reach the holding centre. If you keep them so they don’t know if they’re coming or going it helps in the interrogation and also to identify the leaders. But these guys are in such a mess we’re also having to make sure that we don’t lose any.”

As if on cue, another prisoner passed out and he was lifted to the side of a bank. Corporal Tom Tittley took charge, taking his pulse and advising on treatment. A Royal Marines reservist, his day job is as a paramedic with the London Ambulance Service.

“These prisoners have been in a firefight and most surrendered voluntarily because they were overwhelmed. They are in a terrible state,” he said. “If this is what we’re up against there’s not going to be much of a problem because they’re worn out. There’s people with renal problems, cardiac conditions, another with epilepsy. Basically they are not fit and they shouldn’t be fighting.”

Every five minutes the commandos shouted and gestured for the prisoners to get to their feet, allowing them to stretch their limbs. Those who needed the toilet were led off a short distance behind a boulder.

The Marines’ grasp of Arabic may not be classical but it is at least brief and effective. Each commando carries a pocket-sized laminated sheet of useful phrases: “Ijlis” — sit down, “imshi” — quickly, “Ana jindi Barataine” — I am a British soldier, “Inta sajeen” — you are a prisoner.

Some of the younger prisoners cried silently to themselves, tears making dirty lines down haunted faces. Their peers had blank expressions on their faces, as if only too accustomed to the privations of war. Indeed, it is possible that some of the veterans had seen service in all of the last three conflicts: the Iran-Iraq War of the 1980s, the Kuwait invasion and subsequent expulsion of 1990-91, and this final stand by Saddam, the finality of which might — just might — end their fighting years for good and spare a younger generation of Iraqis the horrors of war.

Eventually two coaches arrived to take them away and the prisoners gratefully shuffled aboard. At the holding centre they will receive medical attention, shower and sleep between clean sheets. They will be given food rations that are clearly superior to those eaten by their captors.

Captain Norman saw them off, the third batch of the day, more than 150 prisoners of war. “I’m tired, I need some sleep, but we’re all still well motivated. We’re in better shape than these guys.

“I still think that they didn’t even know that their command chain had been broken and they were just too scared to surrender: not because they were scared what we would do to them, but what would be done to their families by Saddam if they did surrender.”

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