They had been told they would be protected. Who could have failed to trust the guarantors of their safety? The promise was made in 1993 by the United Nations Security Council and underwritten by four leading powers: the United States, Russia, Britain and France.
Yet, as we reveal today, that pledge was in reality worth nothing. The UN knew it was not equipped to protect the enclaves. Lieutenant-General Bernard Janvier, commander of all UN forces in Bosnia and Croatia, said as much, six weeks before the fall of Srebrenica. He told the UN that the town was indefensible. He went further: the so-called Muslim "safe" areas should, he said, be abandoned to their fate.
And that is exactly what happened, first in Srebrenica and then in Zepa. The great powers stood back and did nothing to halt the slaughter. Air strikes were delayed by Janvier until too late. On the ground, Dutch troops held their fire even as Muslims were being taken away to be shot.
Western inertia during this period has been no secret. We watched the carnage on television. Indeed, the shame of this episode finally forced the protecting powers to do something effective to save the remaining enclaves. But until now, most people had put the debacle in Srebrenica and Zepa down to UN incompetence and blundering. Janvier's confidential statement adds a fresh dimension for it suggests a cold indifference to those offered protection.
No one with any knowledge of previous Serb atrocities could have been in any doubt as to the danger the enclaves faced once they had been abandoned. Yet there seems to have been little or no discussion of any alternative strategy.
It would have been more honest to organise a peaceful movement of the populations from these vulnerable towns. If the major powers would not fight for Srebrenica or Zepa, this would have been a less risky way forward.
There was plenty of time to prepare for the day the Serbs advanced. Militarily, several "safe" areas, particularly those in eastern Bosnia, had always been considered indefensible. What happened in July could have taken place at any time in the previous two years had the Bosnian Serbs launched an offensive. Politically, those drawing up the maps for the eventual peace conference always envisaged that Srebrenica, Zepa and probably Gorazde, islands in a sea of Serb territory, would have to be surrendered.
However, no one faced up to the contradiction between the safe area policy and the long-term military and political realities. For this neglect, thousands of Bosnian Muslims paid a terrible price and the key UN players must bear the greatest responsibility.
Only now, after horrified public opinion and belated leadership from President Bill Clinton have produced concerted action, does there seem to be a more realistic strategy. A defensible line has been drawn and the Serbs have felt the pain of overstepping it. But the credibility of the UN has been severely damaged.
As peace talks open this week in Ohio to settle the Bosnian conflict, those brokering the peace must make sure that they do not again make promises they cannot keep.