1.   However, it also illustrates its fragility.

2.   U.N. peacekeepers came under attack in three different parts of the country, illustrating the fragility of their mission.

3.   U.N. peacekeepers came under attack in three parts of the country, illustrating the fragility of their mission and of international efforts at peace.

4.   U.N. peacekeepers came under attack in three different parts of the country, illustrating the fragility of their mission and of international efforts at peace.