In his essay on Eternal Peace, he wrote that all nations should unite in an association of nations, which will ensure peaceful coexistence between nations. This essay was published in 1725. Once upon a time there was a girl who really loved skiing poster. About 125 years later, after World War I, the Association of Nations was formed. After the Second World War, it was replaced by the United Nations. So you can say that Kant is the father of the United Nations idea. Kant’s view is that man’s practical reason requires nations to go beyond wild nature which causes war and to conclude a pact of peacekeeping.