The 200 French and Ukrainian troops surrounded or disarmed by the Serbs at weapons collection sites and the 16 unarmed military observers (Unmos) used as human shields against further Nato air strikes, are paying the price of the major powers' failure to work out what they want in Bosnia.
General Smith, the British UN commander, has finally forced their hand, escalating the situation to the point where the UN and Nato - which really means Britain, France, Russia and the US - must decide whether to join battle with the Serbs or surrender to them.
The decision to escalate, taken because Gen Smith felt he had exhausted all other options, and cleared at the highest political level, was welcomed by his men. "Without an air strike the credibility of Unprofor [the UN Protection Force] would have collapsed completely," said a French officer in Sarajevo. "We knew that there was a risk on the ground . . . we knew we might be attacked by the Serbs, but it is a risk for all soldiers to take."
The world has deplored the Serbs' taking of hostages. But it has allowed Unprofor - particularly the thousands of troops deployed in Sarajevo and the other government enclaves - to live as potential hostages throughout the war. In the past six weeks, three French soldiers have been shot dead by Serb snipers; two more were killed yesterday.
"This headquarters does not have a problem with escalating," said one UN official. "And this is the 'lite' version of escalation - 70 killed in Tuzla [by a Serb shell], peacekeepers surrounded, Unmos handcuffed to poles. . . [Using force] gave us two options: one was to get the Serbs to comply, and the other was to show the world the absurd nature of having peacekeepers in a semi-enforcement mission."
The choice now, he said, was: "Either we go to war with the Serbs, or we back down." The Serbs, said another official, think they know which way the decision will go, but don't much care: "Now they're in a situation where there is no retreat, they're backed up like a wounded, snarling animal."
The danger of a UN retreat now, though, is that the mission will almost certainly have to abandon the six "safe areas", where they and Nato unite to deter attacks, and the heavy weapons exclusion zones around Sarajevo and Gorazde, and end aid convoys to the five government-held enclaves.
"I hope our government would decide to withdraw," said the French officer. "But we should use the advantage today to confront the Serbs more and more strongly, not to back down again."
It has become personal for the French, who have lost almost 20 soldiers in combat deaths; but it has ever been thus for Sarajevans, who long ago gave up hope that Nato or the UN would rescue them from the besiegers. "We have heard this story for three years now," said Lejla Becirovic, whose flat was destroyed by a Serb shell on Friday. "No one has really helped," she said, tears of shock and anger coursing down her cheeks.
Ms Becirovic was with her two-month-old baby, Haris, at her neighbour's fifth-floor flat when a huge shell crashed through the roof, tearing the floor out of both apartments and plunging both families down to the fourth storey. "They call themselves the UN Protection Force and that's who they protect - themselves," cried Naza Mujic, her neighbour.
The world wanted to help civilians such as these, to feed them, to protect them - but not to fight for them, nor to let their army buy the weapons they needed. The West used the UN to try to contain the Bosnian war. The war will not end because the UN backs down, and civilians will again bear the brunt. Already the Serbs have cut water, gas and electricity supplies to the city.
"What will Nato do about this?" Ms Becirovic cried, gesturing at the ruins of her flat. "My life was in this room, and there is no room anymore."
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