World War I was shocking in the extent of the death and destruction it caused. This was the first war to use a lot of new deadly technology. Airplanes, machine guns, submarines, poison gas, and tanks changed the very nature of warfare. However, tactics did not keep up with the technology. Generals were still using battle tactics devised in the Napoleonic Wars to fight on this new modern battlefield. Having soldiers charge in mass across open fields to be slaughtered by a few heavy machine guns led to incredibly high casualties with little to show for it. Tens of thousands of soldiers could die on a single day. Never before had the world witnessed such carnage.
When the war began in the summer of 1914, many felt that it would be a quick and relatively bloodless war. Recruits were often told it would be over by Christmas. However, as the war quickly turned into a bloody stalemate, it became clear to many that this would be different than ever before.
Civilian deaths as a result of the war were also extremely high. It is estimated that 9.7 million combatants died in the war. However, 10 million civilians also died. Many of these deaths were the result of war-related famine. Many were also killed in bombardments of cities and towns or other military actions. The fact that so few people were safe from the ravages of war was shocking to many.