LAURENCE REES: So then Stalin is obviously proven wrong, and the Germans invade.  Then there’s this hugely controversial period immediately after the invasion when Stalin retreats to his Dacha. What’s your take on that?

SIMON SEBAG-MONTEFIORE: Well, we now know what happened. For years there were these rumours that for a week he collapsed and had this kind of breakdown. A breakdown for Stalin wasn’t quite like a breakdown for anyone else. Even during a breakdown Stalin was still a pretty impressive man of action. Obviously there was incredible shock when the actual invasion started, the denials, the attempt to hope that it was the deserters coming over, that they were just were spies and tricksters, and then the terrible realization, and then belief that you can attack, following the Red Army philosophy. So that goes on for the best part of a week. He’s actually in control minute by minute, I mean, he isn’t really in control because all the armies are in free-fall, he’s ordering counterattacks that never happen and so on, and the Panzers are just storming across Russia. But he’s still sort of running the government with minute detail, day and night, and then after the fall of Minsk on about the 28th of June, I think he just suddenly realises that none of these things are happening, none of the orders he’s given are happening, and he goes to the Defence Commissariat and he goes up there and there’s this extraordinary scene where he goes in with Molotov, Beria and the whole gang and they go in there and Zhukov is there, a man as hard as nails, and Stalin just says where the hell are the armies, you know, what’s going on? And Zhukov says, you know, Comrade Stalin we just don’t know.

And there’s just this terrible moment where Stalin just loses control. It must have been an extraordinary sight, and he just shrieks at them and Zhukov actually bursts into tears. I mean, not just because he’s frightened of Stalin, that was part of it of course, but just the fact that they actually realise they are facing a catastrophe of an incredible colossal scale never, ever suffered before by Russia - ever. And that’s when Stalin says Lenin left this state and we’ve f**ked it up and he just walks out, and he takes his car back to his nearby dacha and he doesn’t appear for three days.  Now, what is he doing? There’s no evidence of him giving any orders, so that is an extraordinary thing. In the middle of this war, at the height of it, as this huge force of several million men are heading for Moscow, here he is just sitting in his house. We’ve no evidence that he did anything. He made no phone calls as far as we know, he signed nothing, what was he doing? We just don’t know. Was he reading the biographies of Kotusov in 1812 where he writes ‘Teacher’, or Ivan the Terrible where he also writes ‘Teacher’ beside the text? In a way he was learning from both those interesting histories. I reckon he probably was reading history books there, as well as being deeply depressed. And so in one sense he did have some sort of collapse, there’s no doubt about it. I think he had a sort of loss of confidence, but he also knew he was facing a colossal loss of credibility and it had to be corrected, and he was also testing people to see what would happen. But he was pretty supine, I mean, he wasn’t arresting anyone or terrorising anyone, he was just waiting. So he was saying come and get me if you have to, but if you don’t come and get me you’ve basically got to re-legitimise me, and you’ve got to re-elect me king, Tsar, you’ve got to take me or leave me.

And so when the leadership came in, he did sit there looking as if they were going to arrest him, and when they didn’t he said: what do you want? And they said we want to make you super dictator, head of the State Defence Committee and with power over everything, as if he didn’t already have absolute power. And he took it, and he basically was just reversing the disasters of the Ribbentrop pact, the disasters of the war, the fact that he totally ignored all the intelligence warnings, the disaster of the surprise attack and the policy of trusting Germany at all; he was basically just drawing a line under it and starting again.

LAURENCE REES: And what’s extraordinary is that people like Molotov went along with this, knowing that Stalin was responsible for one of the greatest failures of leadership in the history of the 20th Century.

SIMON SEBAG-MONTEFIORE: Yes.

LAURENCE REES: Even in the face of this failure, they felt they couldn't remove Stalin from office.

SIMON SEBAG-MONTEFIORE: Well, they all still felt that he was a genius and that he was incredibly impressive and he was an amazing organiser, and it was going to take a huge organiser to do this. There was no one with the authority to do it, no one, and there hadn’t really been anyone since Lenin who had the authority necessary to do this. Trotsky could never have wiped out all the people he did, he was Jewish. Zinoviev, Kamenev, they were all small figures, they were never top ranking figures, but Stalin in a sense was protected by his reputation, by his cult of personality, because to remove him would undermine the whole regime. So they had to keep him, and they felt they needed him.