Imperialism is the policy or action by which one country controls another country or territory. Most such control is achieved by military means to gain economic and political advantages. Such a policy is also called expansionism. An expansionist state that obtains overseas territories follows a policy usually called colonialism (see Colonialism). An imperialist government may wish to gain new markets for its exports, plus sources of inexpensive labor and raw materials. A far-flung empire may satisfy a nation's desire for military advantage or recognition as a world power.