World War 1 saw the emergence of new technologies that changed the nature of warfare. Trench warfare led to new adaptations by soldiers exhausted from living in trenches for weeks. German u-boats effectively sank British supply ships, threatening their navy. Meanwhile, Germany had more advanced aircraft and pilots, making their air force superior to Russia's. Overall, new machines of war like machine guns, submarines, and airplanes caused massive casualties and shaped the outcome of battles and the war.