there was no hint of actually defending the place, numbers of troops
notwithstanding.
Not strictly true. They were under hostile fire yet were unable to gain approval from the UN for air strikes to defend themselves despite very frequent requests. Surrounded, deserted by the UN commanders, and vastly outnumbered, what were they supposed to do? I believe that it was largely this event, by putting NATO troops in jeopardy and not giving them the means to achieve their tasks, that was a major contribution in causing NATO to bring the war to an end by an air campaign.