Trade wars have resulted from attempts by governments to regulate their economies in such a way as to increase their power at the expense of rival countries. This primarily involves attempts to create surpluses of exports over imports. The belief that such surpluses signify national strength and security has led governments to follow policies that have come to be described as 'beggar thy neighbour' policies. By means of tariffs, quotas and devaluation of currencies, governments seek to reduce the entry of foreign goods into their own markets while trying to sell as much as possible to other countries.