As dawn broke in Sarajevo 11 days ago, a handful of soldiers wearing French uniforms, flak jackets and blue UN helmets, drove slowly up to a UN guard post on the southern bank of the Miljacka, chatting in French. The peace-keeper on duty was slightly surprised to see them - 4.30am does not fall within normal visiting hours - and completely unprepared for the shock of having a gun pulled on him by a fellow Frenchman.
The Serbs, who by that time held more than 100 peace-keepers hostage around Sarajevo, had stolen guns, armoured personnel carriers, six light Sagaie tanks and dozens of uniforms, and used them to fool the French. They captured the 12 peace-keepers on duty at the bridge without firing a shot, and without giving the men time to raise the alarm.
Captain Francois Lecointre went to investigate the radio silence from the French positions at Vrbanja bridge, and ran into a Serb soldier, still in French uniform, who told him: "You are a prisoner now." The captain disagreed, did a swift three-point turn and drove the 400 metres back to Skenderija, the former Olympic stadium that houses the men of the 4th French Battalion, known as Frebat4.
Vrbanja bridge is a treacherous place, where the bodies of Sarajevo's "Romeo and Juliet" - he was a Serb, she a Muslim - lay entwined for five days in May 1993. The road is overlooked by the tall buildings favoured by sharp-shooters. The young couple was shot dead by snipers while trying to flee the city. For two years the bridge was a no-go area, but in early 1994 the French deployed troops there in an attempt to calm the tension by interposing peace-keepers between the warring factions.
The Bosnian army had not noticed anything untoward that morning, Col Sandahl said; they expected to see French uniforms on the bridge and Serb soldiers in the buildings nearby, and they did. But there was more activity than normal on the northern bank, where Col Sandahl deployed around 70 men, six Sagaie tanks with 90mm cannon and several APCs armed with 20mm cannon, ready to support the imminent French infantry attack.
Capt Lecointre led his platoon, 30 or so, through the back streets of Kovacici, following the normal patrol route as closely as possible in order not to stir Serb suspicions. As they reached the main road on the south bank of the Miljacka, the captain paused to radio his chief and ensure all were ready. Then he led a frontal assault on the first position, a sand-bagged bunker where French troops sleep on camp beds, protected by metal plates and rolls of razor wire.
"You run," he said, "you run and you shoot." One of his men, Private Jacki Humblot, died in the attack, shot in the stomach. Lt-Col Eric Roussel was involved in the operation. "They ran, because to run was the greatest safety they could have. The one who died was the one who ran the slowest," he said regretfully.
Journalists dozing in the Holiday Inn, 200 metres away on Sniper Alley, were awakened by a ferocious fire-fight involving the French cannon, Serb mortars, anti-aircraft guns, heavy machine-guns and snipers. Cameramen who stuck cameras out of their bedroom windows shot a great deal of sound and fury but little of the battle scene, which was masked by containers set up to protect civilians from snipers and by tall, war-damaged buildings.
Further up the hill on the south bank, the front-line Jewish cemetery was alive with the sounds of war, some of them supplied by French soldiers firing in support of the attack. A second peace-keeper, Private Marcel Amaru, was killed there, shot in the head by a sharp-shooter. Ten French troops were wounded, and another seven had cuts and bruises.
After a battle lasting 32 minutes, the Serbs - who still had control of the second French post and 12 hostages - called a halt. Four Serbs were dead, several were wounded, and four had been taken prisoner by the French. They are still detained at a UN location in Sarajevo and are known here as the "POPs" - prisoners of peace.
"They stopped shooting and decided to talk," Col Roussel said, "to obtain their wounded, to be treated and to get back their dead. We didn't give them back at once. We cared for their dead by putting them in special bags and cared for their wounded with our medical team."
The dead were returned: "I wanted to show them what is normal behaviour for an officer," Col Sandahl explained. "War is war, but you respect international laws." The Serbs later refused permission for a special flight to evacuate the dead and wounded, forcing them to travel in uncomfortable armoured personnel carriers to government-held territory.
Negotiations on a possible exchange of the four Serbs for the 12 French continued all day. "It was a kind of nasty and tricky game, between soldiers - because we are soldiers - and some kind of ragamuffins," Col Roussel said. The talks were interrupted when one of the two French soldiers held in the second post was shot in the leg by a Bosnian government sniper confused, perhaps, by the mix of uniforms. He was freed and evacuated for treatment.
The other French hostages were dressed in Serb uniform and placed in a building close to the bridge as human shields to deter French fire and confuse both the UN and the Bosnian army, Col Roussel said. It was a stand- off, so the Serbs tried another tactic.
"They said, 'If at 8.30pm you don't give back our prisoners, we shall kill your lieutenant and the other soldier', and my men were on their knees in front of the position and we heard them shouting 'They will kill us'," Col Sandahl said. "We said 'no'."
The colonel gazed at the clock ticking away: "29, 30, nothing ... So we had won."
The Serbs melted away in the darkness, and the French corporal still held in the western redoubt, just 50 metres from his comrades, made his escape. "He was in a mood of great excitement because it was a tricky game to escape from those guys," Col Roussel said. "He said it was quite interesting; this was quite strange for him. But all day and all night he had one idea - to escape and reach our lines."
His injured comrade is now doing well, Col Roussel said. "We saw him yesterday on television at a French hospital ... he told the defence secretary this was a great experience, and he was quite surprised to be fired at by the Bosnians." During the actual fight, the Bosnian army joined in with gusto - though not, Col Sandahl emphasised, at the request of the French.
"I suppose the Bosnians were quite excited, and this was an uncontrolled guy who fired at our man," Col Roussel explained. "There was great confusion around the whole area. One of the reasons for our success was we took advantage of that confusion to surround the Serbs and re-take the post."
The soldiers who took part in the attack are back on duty in Sarajevo; 44 comrades from Frebat4 remain in Serb captivity, including 10 taken from the bridge. And the Serbs are still, spokesmen say, "enjoying the hospitality of the UN" - which is probably better than military service in an army that might soon face the full fury of Nato in the UN's proposed rapid reaction force.
"They are well-treated, according to the Geneva Convention - probably for the first time in this war," Col Roussel said. "We gave them food, cigarettes and we allowed them to lie down, to have some rest. They were rather surprised to be treated like that." But those four men may have had only the first taste of a new, robust UN, rather than the supine force that operated, one official said bitterly this year, on the "WIN" principle: "wimpy, ineffective and negative".
Col Sandahl and his commander, General Herve Gobilliard, decided they had to act, despite the risk to their men held hostage; political leaders from the major powers may have to make a similar decision soon. Sarajevo is running out of food, forcing consideration of a UN attempt to blast open an aid route against the Serbs' will, an operation that would undoubtedly prove fatal to any Serbs who disagreed, and also to peace-keepers exposed along so many front lines.
Despite the French dead, who were honoured at a sombre, but proud ceremony at Sarajevo airport, none of the officers in Sarajevo has any regrets about the operation.
"I remain absolutely convinced [the action was necessary] even though we lost two soldiers, which is very painful," Col Sandahl said. "For the first time maybe we changed something in the Serbs' logic ... we had to discuss, to negotiate, to leave, and we didn't. They took the bridge and we took it back."
Col Roussel agrees. "They would have tried again; because of one victory they would say 'Look, the French can be kept and held quite easily'," he said. "The event had local importance but it had global or international importance because of the consequences." He paused and, with the experience of one whose army has lost 39 soldiers, many to Serb snipers, added: "Since the incident, the Serbs are strangely quiet towards us."