-Warfare dramatically increased casualties since civilians were attacked, and more advanced and destructive weapons were available.
-Little medical knowledge, people with shell shocked (PTSD) did not get the medical help they needed.
-Trench warfare (western front- like separating the elaborate trenches of German and Allied positions), would dig trenches, soldiers were stuck there for months or more, led to stalemate, no one was making progress. (ENV)
-Machine guns, bombs, tanks, airplanes, telegraph and telephone, gas weapons all new technologies. There were a lot of spies, some including women. (TEC)