Balance of Power,
a political principle which first came to be recognized in modern Europe in the 16th century, though it appears to have been also acted on by the Greeks in ancient times, in preserving the relations between the different States. The object in maintaining the balance of power is to secure the general independence of nations as a whole, by preventing the aggressive attempts of individual States to extend their territory and sway at the expense of weaker countries. The continued existence of Turkey as a European state has long been due to the operation of this policy among the Christian governments of Europe.
Entry from Everybody's Cyclopedia, 1912.