LAURENCE REES: In May 1940 the Germans invade and conquer France in a matter of weeks. What was the effect of that on Stalin?

ROBERT SERVICE: The fall of France was a disaster for Stalin’s geopolitical strategy, because he had expected the Second World War to be dragged out. He had thought that the French would fight as well as they did against the Germans in 1914, and that didn’t happen. That meant that Stalin had to face the possibility that his alliance with Hitler would be ripped up in Berlin and that all of that stuff in Mein Kampf about Lebensraum in the East would be realised by a military operation against the Soviet Union. So from the fall of France in summer 1940 Stalin’s policy moves from one of contestation with Hitler for the spoils of the various military campaigns towards appeasement. He doesn’t want Hitler to have any thoughts about turning eastwards. The fall of France is a drastic break in the chain of Stalin’s geopolitical thinking.

LAURENCE REES: But when Molotov goes to Berlin in November 1940 he doesn’t really try and appease Hitler?

ROBERT SERVICE: In the second half of 1940 there are negotiations between the Soviets and the Germans, and there’s a steady move towards a more appeasing policy on the part of the Soviets, but they’re subtle about it because they know that if they are too overt in succumbing to Hitler’s demands, Hitler might just be tempted to invade. But after the turn of the year, in the winter of 1940 to 1941, the tone becomes more and more one of appeasement, with Stalin and Molotov going out of their way to stress their friendship for the Third Reich and, indeed, shipping supplies to the Third Reich, which desperately needed raw materials, without demanding on schedule supplies in reverse as part of the terms of the non-aggression treaty of 1939. So Soviet leaders become terrified that Hitler might be tempted, as of course he was.

LAURENCE REES: And what about Stalin’s ignoring of intelligence report after intelligence report that’s suggesting in detail what the Germans are going to do?

ROBERT SERVICE: Stalin was a hyper-suspicious person and he didn’t trust his own intelligence services. In early 1941 he wasn’t getting uncontradictory messages from them. He also had military advice to the effect that if it came to the middle of the summer 1941 it would be too late for the Germans to invade because logistically and climatically it would be a senseless campaign for Hitler to start up. So all of this piled into his mind and bolstered his overconfidence in his own judgement. He wasn’t completely senseless, then, in hoping against hope that Hitler wouldn’t be so senseless. The other thing he had in his mind was that by 1941 Soviet industry was turning out huge quantities of armaments.

The Soviet Army had recuperated from the disasters of the Finnish War of 1939 to 1940. If anyone was senseless in 1941 it wasn’t just Stalin, it was also Hitler. And this bolstered Stalin’s conception that no dictator who didn’t have to go to war would take the risk of going to war unless that dictator was sure of a quick victory. So I think the terrible misjudgment that Stalin made was that dictators aren’t often senseless. Hitler made a terrible misjudgement that he could get away with it.