World War I

Nieuport Fighter, France 1917.

The First World War has been described as clash of twentieth century technology with nineteenth century tactics. Millions of soldiers, both volunteers and conscripts, fought on all sides, with Kitchener's Army being a notable all volunteer force.

Much of the war's combat involved trench warfare, where hundreds often died for each yard of land gained. Many of the deadliest battles in history occurred during the First World War, including the Battles of Ypres, Vimy Ridge, Marne, Cambrai, Sommm, and Verdun and artillery was responsible for the largest number of casualties during the First World War. Vast quantities of explosives were used. Despite having been outlawed by the Hague Conventions (1899 and 1907), chemical weapons such as mustard gas, phosgene and tear gas, and aerial bombardment were used. Casualties from chemical weapons were few but the psychological impact was devastating. Countermeasures such as gas-masks became more effective as the war progressed.

Perhaps the most powerful weapons of the Great War were railway-mounted heavy guns, which became increasingly larger. As each belligerent nation increased the firepower and range of its artillery, the other nations were required to respond likewise in order to prevent the technological superiority of any given military power. The naval guns of the day were the largest guns on the planet, and weighed hundreds of tons apiece. Thus, a method for transporting these guns was essential, and railroads became the favored means. The largest U.S., British, and French rail guns were severely outranged by the German Krupp, Max E, and Paris Guns.

Fixed-wing aircrafts were first used militarily during the First World War. Initial uses consisted primarily of reconnaissance, though this developed into ground attack and fighter duties as well. Strategic bombing aircrafts were created principally by the Germans and British, though the former used Zeppelins (dirigible balloons) to this end as well.

U-boats (submarines) were used in combat shortly after the war began. Alternating between restricted and unrestricted submarine warfare during the First Battle of the Atlantic, they were employed by the Kaiserliche Marine in a strategy of defeating the British Empire through a tonnage war. The deaths of British merchantmen and the invulnerability of U-boats led to the development of several countermeasures: depth charges (1916), hydrophones (passive sonar, 1917), blimps, hunter-killer submarines (HMS R-1, 1917), ahead-throwing weapons, and dipping hydrophones (abandoned in 1918). To extend their operations, the Germans proposed supply submarines (1916). Most of these would be forgotten in the interwar period until World War II revived the need.

Tanks were introduced in World War I by the British and created mechanized warfare that dominated the rest of the twentieth century. The first tank was nicknamed Mother. The first use of tanks was during the Battle of the Somme on September 15, 1916. This was not as successful as intended, but as a start the tanks proved their value against the machine gun. Trenches, the machine gun, air reconnaissance, barbed wire, and modern artillery with shrapnel helped stalemate the battle lines of World War I by making massed infantry attacks deadly for the attacker. The infantry was armed mostly with a bolt action magazine rifle, but the machine gun, with the ability to fire hundreds of rounds per minute, blunted infantry attacks as an offensive weapon; therefore, the British sought a solution and created the tank. Their first use proved tanks needed infantry support and massed formations, but within a year the British were fielding tanks by the hundreds and showed their potential during the Battle of Cambrai in November 1917 by breaking the Hindenburg Line while capturing eight thousand enemy and one hundred artillery guns.

Captive balloons were used as stationary reconnaissance points on the front lines. Balloons commonly had a crew of two with parachutes; upon an enemy air attack on the flammable balloon the balloon crew would parachute. Recognized for their value as observer platforms, they were important targets of enemy aircrafts; fixed, they were also heavily defended by antiaircraft guns. Blimps and balloons helped contribute to the stalemate of the trench warfare of World War I, and the balloons contributed to air to air combat among the aircrafts to defend the skies for air superiority because of their significant reconnaissance value. The Germans conducted air raids during 1915 and 1916 on England with the intent to damage the morale and will to fight of the British and to cause aircrafts to be reassigned to England away from the front lines.