Since World War II the majority of American combat deaths have come from the infantry. This band of brothers, and now sisters, makes up a small minority of the military, but does the bulk of our fighting and dying.
Benjamin Franklin nailed it when he said, "Fatigue is the best pillow." True story, Benny. There's nothing like pushing your body so far past exhaustion that you'd willingly, even longingly, take a nap on a concrete slab.