By Charles F. Bryan Jr. Although World War I was only in its fourth month, the casualties were appalling in their scale. Since the opening of hostilities in early August 1914, nearly 1 million combatants had been killed, wounded, captured or declared missing in action. These horrendous casualty numbers sent shock waves to people throughout the world, most of whom had predicted a relatively short war. In its first three months, the conflict carried many vestiges of 19th-century warfare, with both sides relying on the offensive and large mass attack formations to punch through enemy lines. But two relatively new innovations immediately made offensive warfare unlike previous conflicts.