The use of aircraft in warfare led to great changes in intelligence gathering and tactics. For the first time it was possible for an army to obtain a broad view of the enemy's territory, the positions of his troops and ships, and the state of his defenses. The airplane was also used to attack enemy troops and to bomb supply bases and cities. These innovations led to the development of antiaircraft guns and fighter planes, and expanded the use of camouflage.

Airplanes

The British and Germans staged a few scattered air raids in 1914, but in that year airplanes were used mostly for viewing enemy lines and directing artillery fire. There was little aerial combat.

In July, 1915, the Germans introduced a Fokker fighter plane equipped with machine guns that could fire through the arc formed by the spinning propeller without hitting the propeller blades. With this plane, superior to anything the Allies had, such German pilots as Oswald Boelcke and Max Immelmann won mastery of the air. In February, 1916, the Allies introduced formation flying, and with improved planes, such as the French Nieuports and Spads and British De Havilands, they ended German superiority. One of the early aces was William Bishop, a Canadian, who shot down 72 German planes.

The Lafayette Escadrille, a group of volunteer pilots from the United States, went to France in the spring of 1916. They later would provide an experienced core for the fledgling American Air Service, when the United States entered the war.

In late 1916, the Germans adopted formation flying and with new, superior planes again took the initiative in the air war. Baron Manfred von Richthofen's "Flying Circus" took a heavy toil of Allied fighters. Richthofen shot down 80 Allied planes before he was killed in 1918. The Germans made the first of many airplane raids on London in June, 1917.

During 1918, the Germans continued to outfight the Allies in air battles, but they lost control of the skies to an overwhelmingly greater number of Allied planes.

American air units began to take part in the war in April, 1918. The U.S. Army had virtually no serviceable planes of its own and used British and French aircraft. United States aviators shot down 753 German planes, losing 357 of their own. The greatest United States ace was Captain Eddie Rickenbacker, who shot down 22 planes.

Zeppelins and Balloons

The Germans thought they had an ideal aerial-bombardment weapon in the Zeppelin, or dirigible. The first Zeppelin raid on England occurred January 19, 1915. The large, cumbersome airships proved to be easy targets for antiaircraft guns and fighter planes and were little used after 1916. Only 7 of Germany's 80 Zeppelins survived the war. Observation balloons, protected by antiaircraft guns, proved useful in directing artillery fire.

Colonial Warfare

Colonial warfare was given a low priority on both sides because most of the combatants' resources were reserved for the Western and Eastern fronts. In some instances, there was little fighting, while in one instance hostilities continued up to the Armistice.

The Germans were driven out of Togoland, West Africa, on August 26, 1914, and the colony was divided between the British and French. In the Pacific, New Zealanders occupied Samoa on August 30 and Australia took the Bismarck Archipelago and New Guinea in September. Japanese forces occupied the Marshalls, Marianas, Carolines, and other German islands in November. In China, German troops in Shantung Province surrendered to a Japanese-British force in November.

Forces from the Union of South Africa invaded German South-West Africa (Namibia) in January, 1915, and won the colony in seven months. The campaign in Kamerun (Cameroon) took longer. The colony was invaded by British and French troops in 1914, but the Germans were not driven out until 1916.

In German East Africa (the mainland part of what is now Tanzania) General Paul von Lettow-Vorbeck commanded a force of 15,000 European and African troops. For four years of unceasing tropical warfare with all its hardships, these troops maintained their discipline and morale, wholly without resources except those that they took from their enemy. Local forces in British East Africa were unable to defeat them, and troops were sent from India. These, too, failed. Finally, in the fall of 1916, Afrikaners (South African whites) and Portuguese under General Jan Christiaan Smuts pushed Lettow-Vorbeck into the southeastern corner of the colony.

Lettow-Vorbeck defeated the Allies at Mahiwa in October, 1917, and went on the offensive. When the war ended, he was in the midst of an invasion of northern Rhodesia (now Zambia).