The Japanese were on the offensive for most of the war and used massed infantry assaults against defensive positions, which would later become the standard of all European armies during World War I. The battles of the Russo-Japanese War, in which machine guns and artillery took a heavy toll on Russian and Japanese troops, were a precursor to the trench warfare of World War I. A German military advisor sent to Japan, Jakob Meckel, had a tremendous impact on the development of the Japanese military training, tactics, strategy, and organization. His reforms were credited with Japan's overwhelming victory over China in the First Sino-Japanese War of 1894–1895. However, his over-reliance on infantry in offensive campaigns also led to a large number of Japanese casualties.