The lack of Hollywood-level production values should not take away from the overall quality of this miniseries. The casting and acting is superb and the amount of research must have been incredible. The script lags at some points and there are some anachronisms (most notably the many maps of Europe which show postwar boundaries), but it accurately captures the interplay between three giants of history. It's interesting to note that there are only 5 significant speaking parts (the Big 3 plus Molotov and Hopkins), and the film does a good job capturing the dialogue between them even when they're separate geographically. A simple production that is pure history without unnecessary and distracting dramatic elements -- the history of the time and how the Big 3 interacted with each other produced more than enough drama.
Review of World War II: When Lions Roared
