" Ambushes are complex enterprises, the most difficult task an infantry small unit can undertake, and they’re won or lost in the first few seconds, with the outcome often decided in the very first burst of fire. Seemingly trivial details—the placement of a key weapon, the angle of the sun, a gust of wind, split-second timing in the moment of the first shot—can have disproportionately large effects. "

― David Kilcullen , Out of the Mountains: The Coming Age of the Urban Guerrilla