How is the president's role as chief diplomat connected with the roles of head of state and commander in chief?

As head of state of the U.S. Government meaning the president is the highest ranking member of government he or she represents the United States as the chief diplomat in interactions with other countries. Also given his constitutional powers he or she is also the commander in chief meaning they are in charge of the military with fits with their overall position as head of the executive branch of the U.S. Government.