Among the technological advances throughout the Twentieth Century leading up to The Great War, augmenting the industries of transportation and communication, such as motorized vehicles, mighty steamships and trans-continental trains, telephones and the light bulb, and greatly aiding the military in its efforts to kill more people more swiftly were the rifle and the machine gun, and the "ironclad", replacing the front-loading musket and cannon, and the wooden galleon.
Also, during Britain's illustrious war in Crimea - in the decade preceding America's Civil War, a nurse called Florence Nightingale introduced a standard of care that would soon be replicated as a model for all field hospitals in the treatment not only of incredibly traumatic wounds inflicted on soldiers in battle, but others equally lethal in those days, whether scurvy, infection or severe blood loss. In those days, nearly 80% of British soldiers died from infections obtained in a field hospital - not from their original wounds.
Nightingale helped drop these appalling rates by simply improving hygiene and sanitation in hospitals. Inspired leaders quickly realized it was more cost effective to treat a wounded soldier and get him back to battle than to acquire, train and ship a new soldier to the field. Not only did Nightingale have a profound influence on the rapid modernization of hospitals and their care of the sick and wounded, but on their hiring practices. By delivering female nurses to the field, it allowed more men to be deployed as soldiers or battlefield medics.
After the Crimean War, medical reform was deemed critical; for instance, typhus typically contracted in ambulances was eliminated, beds were provided in field hospitals, as were antiseptics, and soon enough doctors were able to save broken limbs as opposed to amputating them. In essence, following the Second Boer War, the war machine was well-oiled. Troop numbers could now be raised in great numbers, transported efficiently and treated effectively if wounded, in the light of day or at night, and most importantly enemy soldiers could be mowed down from a distance.
Mobilization in 1914 meant massive armies were on the move. For each nation intent on going to war, acquiring the right men to fight was finding a balance between capacity: of their professional administrators and recruiters during the Marketing and Enlistment phase, educators and trainers to provide the necessary skills (and separate the men from the boys) during the Assessment and Allocation Phase, and drivers and shippers during the Transportation and Deployment Phase. Patriotism, solely, would not win wars. Winning required planning.
At the behest of Nicholas II, and the various members of the ambitious Romanov family who had ruled the country for 300 years, Russian planners eagerly sent millions of men to their deaths on the Eastern Front, poorly trained and ill-equipped against an incredibly efficient German killing machine. It was an effort that had obviously a devastating effect on the Russian men and women lost in battle, but also for the monarchy. Nicholas committed his army, and backed Serbia, to maintain control of the Balkans, whose borders lined up against the empires of Germany and Austria-Hungary.
After Franz Ferdinand was assassinated, the leaders of Austria-Hungary had issued an ultimatum to Serbia, notwithstanding the fact that Serbian nationalism represented a major threat to its empire, which contained more Slavs, including Bosnian Serbs, than either Austrians or Hungarians. The German empire supported the Austrians because Austria-Hungary was its only reliable ally in Europe. France supported Russia to regain the provinces of Alsace and Lorraine, previously lost to Germany in the Franco-Prussian War of 1870-71.
Britain entered the war because Germany attacked Belgium, though moreso due to an increasing industrial and military competition with Germany. It's worth noting Germany prior to 1918 won more Nobel prizes Britain, France, Russia, and the United States combined, a formidable industrial, technological and scientific sleeping giant. As well, Germany at the start of World War One boasted a navy to rival the British, keeper of the waves. Germany attacked Belgium because of its plan to minimize the consequences of having to fight against both France and the Russian Empire.
Upon being placed in the field, soldiers in large numbers faced each other and fought when commanded to do so, bravely standing as one. United, they each fought for King and Country. They each fought believing God was on their side. In order to regain Alsace-Lorraine from Germany, which they succeeded in doing with the signing of the war-ending Armistice after four years of constant fighting, France had lost 30% of its men between the ages of 18 and 28 in the process.
At the outset, nations were limited by numbers, and struggled to match eager recruits with the right weapon: no longer thinking in terms of one rifle per soldier, as a machine gun might require a crew of four, and long-range artillery a crew of a dozen or more. Throughout the war, new weapons were developed and brought forward to the front, including the bayonet, flamethrower, grenade and tank, not to mention poison gas, airplanes (as well as air traffic control), aircraft carriers, depth charges, torpedoes, tracer bullets and trench mortars.
Prior to the Great War, blood transfusions were risky and not often used by doctors. However, Major Lawrence Robertson of the Canadian Army Medical Corps successfully performed a number of direct donor-to-patient transfusions in the field without cross-matching blood types. In 1917, Captain Oswald Robertson of the U.S. Army Medical Officer Reserve Corps demonstrated blood could be donated in advance and stored using sodium citrate as an anticoagulant, and thus is credited with developing the first blood bank.
With respect to advances in medical technology, Marie Curie had begun to create mobile X-ray stations for the French military immediately after the outbreak of war, and by October 1914 had installed X-ray machines in several cars and small trucks which toured smaller surgical stations at the front. By the end of the war, 18 of these "radiologic cars" or "Little Curies" were in operation.
Also, the modern sanitary napkin was made possible by the introduction of new cellulose bandage material during the First World War, and innovative French nurses quickly determined that clean and absorbent cellulose bandages were far superior to any washable or disposable undergarment. Kinmberly-Clark a few years later commercialized the napkin and introduced their Kotex brand.
In addition to the good deeds of researchers, scientists and engineers, who were tasked to repair the millions of men who were returning home scarred and shattered forever, it should come as no surprise, at the the United States' Walter Reed Hospital, the goal of their Artificial Limb Laboratory, which opened in 1917, was to give every soldier amputee a modern limb so he could return to work.
