Columbia subject headings:
Harvard subject headings:
Isolationism--United States--History.
Trump, Donald, 1946-
United States--Foreign relations--2017-2021
United States--Foreign relations.
Princeton subject headings:
Isolationism--United States--19th century.
Isolationism--United States--20th century.
Isolationism--United States--21st century.
United States--Foreign relations--19th century.
United States--Foreign relations--20th century.
United States--Foreign relations--21st century.
United States--Politics and government.