Responsible in example sentence
If that Martian looked at battlefields, they would find that people had only muskets at the time of the Civil War and that they had repeating rifles at the time of the Spanish-American War, and then they had machine guns by the time of World War I. And, in other words, it was the equipment that was in the hands of the average soldier that was responsible, not greater keenness of eye or steadiness of hand.