The makeup of the World War I force shown in the image is best explained by the fact that by 1917, the war had been raging for three long and bloody years. With the armies of Europe locked in a stalemate, both sides were desperate for a breakthrough. This led to a marked increase in the number of forces being deployed in the war.
By 1917, the Allies had mobilized an estimated twelve million military personnel for the war effort. This included troops from Great Britain, France, the United States, and the other countries of the Entente powers. On the German side, the Central Powers had an estimated eleven million troops at their disposal. This included troops from Germany, Austria-Hungary, Bulgaria, and the Ottoman Empire.
The troops that made up the force shown in the image were largely made up of infantry. Infantry troops were the backbone of the war effort and were used in all aspects of the war, from the front lines to the supply lines. Infantry troops were used to assault enemy positions, protect and hold ground, and carry out logistical operations. In addition to the infantry, the force also included cavalry, artillery, and air forces.
Cavalry was used to scout the enemy, to harass and disrupt the enemy, and to provide mobility in the face of the enemy. Artillery was used to bombard enemy positions from a distance and to provide cover for advancing troops. Air forces were used to provide reconnaissance, to bomb enemy positions, and to provide air cover for advancing troops.
In addition to the military personnel, the force included a number of support personnel, such as doctors, nurses, cooks, and mechanics. These support personnel were essential to the war effort and provided much-needed services to the troops on the front lines.
The makeup of the World War I force shown in the image is a testament to the scale of the war effort at the time. By 1917, the war had been raging for three years and the forces of both sides were desperate for a breakthrough. This desperation led to a massive mobilization of troops and support personnel, resulting in the force depicted in the image.