Complex sentence: Zbigniew Kazimierz Brzezinski (;; born March 28,1928) is an American political scientist and geostrategist, who served as a counselor to President Lyndon B. Johnson from 1966 to 1968 and was President Jimmy Carter's National Security Advisor from 1977 to 1981.
Split into simpler sentences: Zbigniew Kazimierz Brzezinski (;; born March 28,1928) is an American diplomat and political scientist. He served as a counselor to President Lyndon B. Johnson from 1966 to 1968 and was President Jimmy Carter's National Security Advisor from 1977 to 1981.