Explain to what extent nato is membership in this organization was a continuation or departure from us foreign policy

See if this helps "North Atlantic Treaty Organization (NATO) was founded on 4 April 1949 in Washington, D.C. On behalf of the United States, the North Atlantic Treaty was signed by Dean Acheson, secretary of state throughout President Harry S. Truman's second term. The founding members of the Atlantic alliance consisted of the United States, United Kingdom, France, Canada, Norway, Denmark, Iceland, Belgium, the Netherlands, Luxembourg, Portugal, and Italy. The U.S. Senate ratified the treaty on 21 July 1949 by a vote of 82 to 13 "