In analyzing the coming great war, Ivan Bloch noted that the strain of marching is very heavy:
Remember that it is not mere marching, but marching under heavy loads. No infantry soldier should carry more than one-third of his own weight; but instead of the average burden of the fully accoutred private being 52 lb. it is nearer 80 lb., with the result that the mere carrying of weight probably kills more than fall in battle.
The proportion of those who die from disease and those who lose their lives as the consequence of wounds received in fighting is usually two or three to one. In the Franco-German war there were four times as many died from sickness and exhaustion as those who lost their lives in battle. In the Russo-Turkish war the proportion was as 16 to 44. In the recent Spanish war in Cuba the proportion was still greater. There were ten who died from disease for one who fell in action.
The average mortality from sickness tends to increase with the prolongation of the campaign. Men can stand a short campaign, but when it is long it demoralises them, destroys the spirit of self-sacrifice which sustained them at the first in the opening weeks, and produces a thoroughly bad spirit which reacts upon their physical health.