On 1 may 1941 Nazi Germany and Stalin's USSR held a common military parade in Moscow as part of the Ribbentropp-Molotov Pact. The pact also included broad Commercial Agreements which allowed Nazi Germany to bypass international trade blockade as it conquered Western Europe and prepared attack on USSR itself in June that year. If you're wondering if this video is authentic, this is an extract from what was originally published by Russia's own military channel TV Zvezda on 9 July 2012 in the series "History of military parades on Red Square, film 2". The original black-and-white fragments in turn come from the 1941 Soviet TV chronicles.