" Hitler had done quite enough in his career to prove how utterly untrustworthy he was long before the Nazi–Soviet Pact was signed in August 1939, yet as Alexander Solzhenitsyn pointed out: ‘Not to trust anybody was very typical of Josef Stalin. All the years of his life did he trust one man only, and that was Adolf Hitler. "

― Andrew Roberts , The Storm of War: A New History of the Second World War