After the defeat in the naval battle near Heligoland (August 28, 1914 loss of three cruisers), the German ocean-going fleet was held back. The advance against the British east coast led to the naval battle on the Dogger Bank (January 24, 1915), which was also unfavorable for the German Navy, with the loss of the battle cruiser »Blücher«. Thereupon Germany began the unrestricted submarine war (February 4, 1915) with the torpedoing of warring and neutral merchant ships without warning in the waters around Great Britain that had been declared a maritime war zone. After the torpedoing of the British passenger steamer »Lusitania« (May 7th, 1915 Lusitania incident), in which numerous American passengers were killed, the threat of war from the USA forced the German leadership to give in: Germany returned to limited submarine warfare in British waters.

Increased efforts by the German deep-sea fleet to provide at least parts of the British Home Fleet led to the battle off the Skagerrak (May 31 / June 1, 1916).

According to ebizdir.net, the British losses in ships and crews were about twice as high as the Germans. Despite the tactical success – the German deep sea fleet had twice withdrawn from the threatening British grip from an extremely unfavorable situation – the British naval superiority could not be called into question. The German battle fleet was condemned to inaction in the North Sea. Short-term consequences were the renewed decision to unrestricted submarine warfare, which came into force on February 1, 1917, followed by the United States’ entry into the war against Germany (April 6, 1917); the medium-term consequence was the demoralization of the fleet, which became evident in naval mutinies at the end of the war.

The colonial war 1914-18: When the war began, the Entente immediately attacked the German colonies (protected areas). Togo was occupied by the British and French in August 1914. In the summer of 1915, the protection force in German South West Africa was subject to ten-fold South African superiority. The protection force in Cameroon asserted itself against far superior Allied forces until the beginning of 1916 and then transferred to Spanish territory. General P. von Lettow-Vorbeck successfully defended German East Africa against all Allied incursions until February 1916; on November 14, 1918 he finally gave up on the orders of the Reich government. Tsingtau fell into the hands of the Japanese on November 7, 1914. The German South Sea islands were occupied by Japanese and Australians in 1914.

The aerial warfare 1914–18: At first the occasional long-range reconnaissance, after the transition to trench warfare, the close-up reconnaissance by airplanes played a role. Air battles only gradually broke out in the course of the war (first German victory over a French aircraft on November 5, 1914); This went hand in hand with a targeted arming of the aircraft (Flieger-MG, high-explosive bombs and incendiary bombs) and the development of various types of aircraft (reconnaissance, fighter and bomb aircraft as well as attack aircraft; the most powerful German fighters: Albatros D III and Fokker D VII). Zeppelin airships dropped bombs over Antwerp at night in 1914 and in 1915/16, among other things. via London and Paris.

German combat squadrons were deployed near Verdun in 1916. In October 1916 all German air and air defense forces were combined under one commanding general of the “air force”. By the end of the war, the aviation forces of the Central Powers and the Allies were considerably strengthened (the number of military aircraft rose by an average of 10 to 15 times between 1914 and 1918). The use of low-level planes and bombers against the ground forces increased considerably up to the mutual offensives of 1918; Towards the end of the war, despite violent attacks by the German fighter squadron (most successful fighter pilot M. von Richthofen ) especially against the “Royal Flying Corps” – the air superiority of the Allies (in April 1918, among other things, the establishment of the British “Royal Air Force”) was becoming more and more apparent.

The First World War was characterized militarily by the mass use of new technical weapons; the production of airplanes, tanks (tanks) and machine guns skyrocketed; chemical weapons (gas) and flamethrowers were used for the first time.

With the further development of war technology, new branches of the armed forces and types of weapons (air, tank, intelligence and guest troops) emerged; the firepower of the infantry and artillery increased considerably. Special guns were developed for anti-tank and anti-aircraft defense. The cavalry became less important.