League of peace is an expression coined by Immanuel Kant

Immanuel Kant

Immanuel Kant was a German philosopher from Königsberg , researching, lecturing and writing on philosophy and anthropology at the end of the 18th Century Enlightenment....

 in his work Project for a Perpetual Peace

Perpetual peace

Perpetual peace refers to a state of affairs where peace is permanently established over a certain area .Many would-be world conquerors have promised that their rule would enforce perpetual peace...

. The league of peace should be distinguished from a peace treaty

Peace treaty

A peace treaty is an agreement between two or more hostile parties, usually countries or governments, that formally ends a state of war between the parties...

, or pactum pacis, because a peace treaty prevents or terminates only one war, while the league of peace seeks to end all wars forever. This league does not hold any power of the state but only exists for "the maintenance and security of the freedom of the state and of other states in league with it, without there being any need for them to submit to civil laws and their compulsion, as men in a state of nature must submit."