Modern warfare particularly depends on oil, because virtually all weapons systems rely on oil-based fuel – tanks, trucks, armored vehicles, self-propelled artillery pieces, airplanes, and naval ships. For this reason, the governments and general staffs of powerful nations seek to ensure a steady supply of oil during wartime, to fuel oil-hungry military forces in far-flung operational theaters. Such governments view their companies' global interests as synonymous with the national interest and they readily support their companies' efforts to control new production sources, to overwhelm foreign rivals, and to gain the most favorable pipeline routes and other transportation and distribution channels.