The need for natural resources and to protect wealth and commerce has played a major role in many wars. Even US entry into World War II, which could hardly be reduced to a single cause, was directly influenced by Japanese desire to control oilfields in the Pacific. One of the stated objectives of US entry into World War I was to protect American trade rights. Trade has been a very common reason (or more accurately, one of the reasons, as wars seldom have a single cause) for wars in the past, including most of the conflicts between England and France during the eighteenth century. Even the Hundred Years War, which had its roots in a dynastic issue, was also a result of English desire to control the very wealthy regions of Gascony and even Flanders. The causes of most wars, in the final analysis, are traceable to some extent to economic issues.