Aside from the victory-defeat relationship which led to political realignments during the post-war years, the essence of the experience is to be found in the UNESCO phrase "weakened in every way". Another way of describing the experience is to state that the participants in this four year blood bath were "bled white."
It is easy to be specific. In the course of the war sixty million people were mobilized. Most of these people stopped what they had been doing until mid-summer of 1914 and began an entirely new line of activity. Up to that point most of them had been living with their families, in their neighborhoods, going through a daily routine that included household cares, production or service work, the conduct of neighborhood affairs, the maintenance of normal livelihood activities, the upbringing of the new generation and perhaps most important of all, adaptation to a rapidly changing social situation.
The changes that took place in the summer of 1914 involved an almost complete reversal of purpose and direction. Up to that point Europeans were devoting a considerable proportion of their time to production and the maintenance of the normal life routine. At that point they left their homes, exchanged ordinary clothes for uniforms, laid down the implements of peace, picked up the weapons of war and prepared, under very expert leadership and direction, a series of mass movements designed to disrupt the ordinary life routine of other human beings on the other side of lines drawn on a map, but having little relation to customary life activity and even less to geography.
Execution of this purpose involved a mass movement from the home territory into that occupied by the "enemy". If the enemy resisted he must be forced to do the will of the invaders. Instead of cooperating in a joint effort to maintain and improve the general welfare, uniformed, armed, expertly-led masses began beating up each other, until one side gave in and cried "enough."
Plans for war had been drawn and redrawn for years, for decades. Elaborate preparations had been made. Destructive weapons had been designed and built. Transport had been provided, food stored. Defensive preparations had also been made in the form of fortifications so placed as to obstruct or prevent "the enemy" from crossing the "frontier".