Sentence:  The ultimate objective of American policy is to help establish a world in which there is the largest possible measure of freedom and justice and peace and material prosperity ; and in particular - since this is our special <WSD>responsibility</WSD> - that these conditions be enjoyed by the people of the United States . 
Meaning of the word marked with <WSD> tags:  the social force that binds you to the courses of action demanded by that force; every opportunity, an obligation; every possession, a duty"- John D.Rockefeller Jr