Winston Churchill once said: "Those that fail to learn from history are doomed to repeat it." Those words ring as true today as they did in 1948. Churchill, who served in the First World War before he led Britain through the Second, knew all too well the miscalculations that presidents and prime ministers made leading up to the Great War.

A century later, the UN's top diplomat, Secretary-General António Guterres, fears that world leaders today are making the same mistakes that got us into WWI. In an exclusive interview for GZERO World with Ian Bremmer, Guterres explains what makes him so wary of this moment in geopolitics.