There is then much debate about whether Chamberlain thought he had bought time by refusing to fight over the Sudetenland, or whether he genuinely thought, in his own phrase, that he had secured “peace in our time”. Some historians are so keen, even 85 years on, to prevent Chamberlain from having any sort of posthumous reputation that they refuse to acknowledge the eternal truth that politicians will say one thing for public consumption while pursuing another policy away from the public gaze.

If Chamberlain was so sure he had guaranteed peace, why did British rearmament step up dramatically after his return from Munich? The assumption that he trusted Hitler to keep his word cannot be relied upon. Bouverie stresses that Chamberlain never used the argument about buying time: but then he didn’t need to. The time came in 1938–9 when actions spoke more loudly than words, and Chamberlain, despite what his critics maintain, acted by rearming. 

Professor Evans is right to say in the documentary that Chamberlain was forced into war. And, as Professor Charmley says, once he was, everything he dreaded – notably the early defeats, the Blitz and the eventual loss of empire – came true. Near the end of the programme it is stated that Lord Halifax turned down an offer to replace him: but that offer was never made. 

The only person able to make it, George VI, acted on Chamberlain’s recommendation in May 1940 and sent for Churchill. The rest, as they say, is history – and is as open to dispute as much else presented by this documentary as unanswerable fact.

Could Hitler Have Been Stopped? The Politics of Appeasement begins on April 5 at 9pm on 5Select