foreign policy, general objectives that guide the activities and relationships of one state in its interactions with other states. The development of foreign policy is influenced by domestic considerations, the policies or behaviour of other states, or plans to advance specific geopolitical designs. Leopold von Ranke emphasized the primacy of geography and external threats in shaping foreign policy, but later writers emphasized domestic factors. Diplomacy is the tool of foreign policy, and war, alliances, and international trade may all be manifestations of it.