Who is Joachim von Ribbentrop from the nonfiction book, Inside the Third Reich: Memoirs?

Joachim von Ribbentrop is Adolf Hitler's Foreign Minister, previously his ineffective Ambassador to London. Ribbentrop is ostentatious and unpopular among his scheming colleagues. Opposing war in 1939, Ribbentrop negotiates a friendship pact with Josef Stalin that frees Hitler to attack Poland and France.