Militarism led to leaders stockpiling weapons and increasing army size. By 1914, Germany's army compared to Britiain's. Germany and Britain began to battle at sea while Germany, France, and Russia battled on land. Throughout this time, deadly modern technology was evolving. Weapons such as machine guns, artilery field guns, poison gas, submarines, tanks/armored cars, and airplanes all contributed to the casualties of the war. The US sayed out of arms race for three years.