Rise of Modern Warfare: WW1
Poison Gas: Initially introduced by the German army, poison gas was used on all battle fields. It caused blisters, blindness, and death by asphyxiation. Poison gas changed warfare because it was simple and discrete; armies no longer has to be present in a battle field to kill their opponent, but they were now able to just place the poisonous gas in fields and surprise attack men.
Machine Gun: This new type of gun automatically fired bullets and killed larger amounts of people with less effort. By inventing the machine gun, it changed warfare with its advanced, time-efficient ways. Soldiers did not have to reload their guns as often and were able to take more lives with the ammunition they had.
Tank: When the British first created the tank during World War 1, one of the main purposes was that it could cross through difficult ground and land. This invention changed warfare because armies were now able to travel more difficult paths with more safety; therefore, military leaders could invade more often with more confidence and less concern.
Submarine: The submarine's main purpose was to be one of the first effective effective water war caft besides the ship. With submarines came the beginning of torpedoes; the submarine changed the war because battles on the sea became more abundant having a strong naval force became even more important.