1.   Authorities here also worry that preparations to use U.S. Apache attack helicopters to target Serb forces along the border could provoke Serb retaliation against the refugees.

2.   On further checking, he has found no evidence to substantiate that there was Serb retaliation.

3.   The Europeans, furious that the U.S. administration would expose their ground troops to Serb retaliation, lectured Christopher, who came back empty-handed.

4.   Western European nations, who have the bulk of the peacekeeping forces in the former Yugoslavia and fear Serb retaliation, quickly complained that the U.S. action was reckless.

5.   A tougher stance would need approval of the United Nations, which has opposed aggressive action for fear of Serb retaliation.

6.   Afraid of Serb retaliation with heavy artillery, residents of Sarajevo piled sandbags in front of windows and other vulnerable sites Wednesday.

7.   Also at risk are those very same U.N. peacekeepers, likely to become targets of Serb retaliation in the event of air strikes.

8.   Any tougher stance would need approval of the United Nations, which has been reluctant to authorize aggressive action for fear of Serb retaliation.

9.   Both countries fear NATO attacks would trigger Serb retaliation against their peacekeeping troops.

10.   But they fear Serb retaliation during the pullout, and have declared their right to defend the civilian population.