KABUL, Afghanistan  No one seems certain who fired the first shot in the early morning hours of Dec. 24 as commandos from the coalition forces here descended on a Kabul office building in search of two cars loaded with explosives.

It may have been one of the Afghan security guards manning the gate, but two of them are dead. Or it may have been one of the commandos, or someone in the Afghan special forces accompanying them on the night raid, as they tried to prevent what they had been told was a coming Christmas Day attack against the United States Embassy.

What is certain is that a shootout at the headquarters of the Afghan Tiger Group, a supplier of vehicles to the United States military, left two Afghan guards dead and two wounded, terrified dozens of Afghan civilians, and once again raised tensions between the coalition forces and the Afghan government over such night raids, which have long been a source of friction.

An examination of the raid  which turned up no explosives  and the widely diverging accounts of events show the difficulties the coalition forces face in winning public opinion for such military operations. Darkness, the coalition’s military advantage in such raids, becomes an obstacle to civilians’ safety and understanding of events.