How does World War 1 effect the way you fight now?

Many things about World War I (The Great War) had effects on how we fight now.

The most significant was the concept of aerial warfare. No longer could armies move up reinforcements for huge assaults without being noticed. If you wished to prevent an opponent seeing what you were doing it had to deny airspace above the battlefield. Now any country without a viable air force to deny airspace and provide close air support cannot hold territory let alone take territory.

One thing was the machine guns. These guns, such as the British Vickers or German Maxim, made charges and the Calvary obsolete. Another aspect is that cavalry were replaced by armored tanks.

In World War II the Germans revolutionized the principles learned from the battles and technology of WWI.

Another effect was the use of submarines to deny trade and re-supply. The U-boat (short form of untersee boot - German for under sea boat). In fact, the U.S. entered the war after the Lusitania was sunk by a German U-boat. In WWII submarines would play an important part in the sea war.

The last effect was the creation of the League of Nations; Woodrow Wilson's brain-child that is widely regarded as a precursor to the United Nations. The League of Nations was an attempt to moderate disputes and avert Wars.