How did world war 1 change in way in which wars are fought?

Answer 1

A plethora of new weapons were invented that changed both tactical and strategic battle. Many of the developments since the US Civil War were brought together for the first time in mass combat.

The weapons included machine guns (successors to the Gatling gun), poison gas, armored vehicles (tanks), masses of long range artillery, and most importantly the airplane. As seen in some earlier regional conflicts, aircraft could attack well behind enemy lines, scout out enemy troop movements, and carry messages between widely separated commands.

Armies marching in an open field and facing each other in formations, commonly known as "maneuver warfare," gave way to trench warfare. Troops out in the open were too vulnerable to attack. World War I was also the beginning of mechanized warfare.

At sea, armored dreadnoughts were the mightiest of ships, but the newest innovation was the effective use of submarines (U-boats) against both capital ships and against transport ships carrying war materials.