The First World War was the first modern industrial war. For the first time, it saw the use of machine guns, tanks, aircraft, chemical weapons etc on a massive scale. During this time, the world experienced economic and political instability.
These were all products of modem large scale industry
(i) To fight the war, millions of soldiers had to be recruited from around the world and moved to the front lines on large ships and trains.
(ii) The scale of death and destruction was devastating, 9 million people dead and 20 million injured, which was not possible without the use of industrial arms.