Neville Chamberlain has endured a savage historical appraisement. He’s the prime minister who failed to stand up to Hitler. The politician who didn’t understand the existential threat posed by the fascist leader and his Nazi ideology. The man who bundled things so spectacularly with his policy of appeasement that Europe plunged into devastating conflict that cost millions of lives.

But “Munich: The Edge of War,” an adaptation of Robert Harris’ novel, presents a far more sympathetic portrait of Chamberlain, and it’s one that hasn’t been sitting all that well with some historians and critics. As played by Jeremy Irons, Chamberlain is so scarred by the carnage of World War I that he will do anything to prevent more violence, even if that means allow Germany to annex the Sudetenland, a section of western Czechoslovakia that proved to be only the first stop in Hitler’s unquenchable territorial ambitions. Chamberlain, at least the one presented on screen, is also aware that the United Kingdom is not yet on military footing and must contain Hitler until it can build up its defenses. “Munich: The Edge of War” co-stars George MacKay and Jannis Niewöhner as low-level British and German diplomats who become entangled in the fraught geopolitical moment.

In advance of the film’s premiere on Jan. 21 on Netflix, Irons spoke with Variety about reevaluating Chamberlain, the future of cinema and why he hasn’t seen Zack Snyder’s director’s cut of “Justice League.”

How did you get cast in “Munich: The Edge of War”?

Robert is a friend. We were actually having lunch in London to talk about another project that he had in mind and he was at that point writing “Munich” and he said he found himself sitting opposite me thinking, “Jeremy would be a very good Chamberlain.” From there on, he sort of thought of me as he was writing. He sent me the book once it was printed and I was fascinated by the story and the character and emailed him to say “I’m your man if you want one.” Eventually it was picked up by Netflix as a two hour film and the producer and director thought it might be a good idea to have me.

What was the other project you’d been talking to Robert Harris about doing?

It was the one about the cardinals and the election of a pope, “Conclave,” which I think is now being made as a film or a series by somebody.

Are you still involved in the adaption of “Conclave”?

No, they haven’t asked me.

Did you know much about Chamberlain before you were cast?

No, I learned about him from the book. I went a little bit wider and watched some news footage of him and read some of his speeches. I drilled into his political history, but I got the feeling of the man from Robert’s book.

Were you surprised by what you found out about Chamberlain?

He comes down as a minor-ish historical character who appeased Hitler and was fooled by Hitler. He died just before the war really started. He seemed slightly old fashioned in his time, slightly Edwardian. Churchill is such an overwhelming historical figure. He wrote his autobiographies and he had wanted to go to war in 1937 and was very pugnacious. Chamberlain believed the country wasn’t ready either militarily or emotionally. He was also enormously affected, as the whole country was, with a kind of post-traumatic stress disorder from the first World War when millions of our sons, fathers and whatever had been killed. The idea of going to war again some 20 years later was anathema to Chamberlain and he did everything in his power to put it off.

Churchill was able to write the history of that period afterwards. It’s all very easy to look back at history and see what you want to see. But at the time, I believe Chamberlain followed the right path. He tried to prevent war. He tried to appease Hitler and got an agreement with Hitler that he would go no further. That was a canny thing to do because once Hitler did go further, he was able to say to the country, this man is not to be trusted and we’re going to have to fight him. Munich was an agreement that Hitler always bitterly regretted and he blamed Chamberlain for his failure to win. He thought had they gone to war in 1938, the Nazis would have crushed the British and won. I think Chamberlain should be praised for his pragmatic behavior. We shouldn’t view the Munich Agreement simply as the appeasement of a weak man who was fooled by Hitler. It’s the wrong way to look at it.

There are op-eds and articles suggesting that “Munich: The Edge of War” is too sympathetic to Chamberlain and lets him off the hook. What do you think of the pushback?

Historians will always find their corner. They all have their opinions. I’m not surprised there’s pushback because in many people’s eyes Chamberlain was unsuccessful. He didn’t stop the war. But Robert’s reappraisal is extremely important and may sway some minds.

Where should we draw the line between appeasing tyrants and going to war?

We have to prevent war at any cost. It’s always a very difficult balance and we see dangers still around us. Things don’t change — whether it be Ukraine or North Korea or Belarus. My feelings are looking at the history of war that we have to do everything in our power, diplomatically and economically, to dissuade military conflict. Because military conflict always creates more problems than it solves. We see that with Iraq. We see it in Syria. We should try to learn from history and see Chamberlain was on the right track. It didn’t work, but at least he tried.

What was the key to cracking Chamberlain as a character and not just a remote historical personage?

I saw he’d been a very good mayor of Birmingham and housing minister in England. He’d been a very successful chancellor of the exchequer. He was the son of a politician, so politics was in his blood and leadership was in his blood. But I fought for an extended version of a scene in Downing Street garden where we see Chamberlain’s gut-horror at going to war. It’s the nearest we get to naked emotion with him. We needed that bedrock to understand where he’s coming from with his diplomatic machinations. We know what his heart feels.

Ten years ago a movie like “Munich: The Edge of War” would premiere exclusively in cinemas. Now, it will mostly be viewed on Netflix. What do you make of that shift?

Things change. The golden age of cinema is over. I think it will still be a wonderful place to go, so I don’t think cinemas will die out completely. Of course, things are exacerbated at the moment with COVID. We’re not supposed to get together in large numbers and our habits over the last couple of years have really changed. It will be interesting to see when we come out of the terror of this pandemic, how society develops. I hope people will still gather in cinemas to see movies that need to be seen on the big screen. In a way, “Munich” doesn’t need to be seen on a big screen. It’s not David Lean or even Ridley Scott. It’s not hugely magnificent. But I think the human need to gather together and watch movies or theater or listen to music will always be there. I hope we’ll start doing it again soon.

You played Alfred Pennyworth in “Justice League.” Have you watched “The Snyder Cut”?

Strangely, I think I have it and I haven’t seen it. I shall have to hunt it out and see if I have it somewhere online or on a DVD. I remember talking to Zack [Snyder] before he did it and being very interested to see what he came up with. It couldn’t have been worse.

You mean “Justice League” couldn’t have been worse?

I don’t think it could have been, could it?

I thought it was dreadful.

Well, so did I.