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 <WSD>is</WSD> our special responsibility - that these conditions be enjoyed by the people of the United States . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)