Since the end of the Second World War, the United States has been the premier global power. Our modern presidents from Harry Truman to Barack Obama have coordinated that power in the White House principally through the National Security Council (NSC). The NSC was created in 1947, along with the Department of Defense and the CIA, to modernize the way Americans made foreign and defense policy after the crucible of World War II and as the Cold War was just starting.
Burns, Nicholas, Joseph S. Nye, Jr. "Preface." America’s National Security Architecture: Rebuilding the Foundation. Ed. Burns, Nicholas and Jonathon Price. Aspen Institute, 2016.