Sentence:  In a book review of `` The Soviet Cultural Offensive '' , he says , `` Long before the State Department organized its bureaucracy into an East-West Contacts Staff in order to wage a cultural counter-offensive within Soviet <WSD>borders</WSD> , the sharp cutting-edge of American culture had carved its mark across the Russian steppes , as when the enterprising promoters of ' Porgy and Bess ' overrode the State Department to carry the contemporary ' cultural warfare ' behind the enemy lines . 
Meaning of the word marked with <WSD> tags:  a line that indicates a boundary