I’m not sure which Michael Moore I’m going to get when I call him in New York. Will I get the slightly cantankerous Michael Moore of the documentaries? The one who knocks on people’s doors and doesn’t take no for an answer? Polemical Michael Moore who savaged George W Bush in his documentary Fahrenheit 9/11? Or the playful, amused Michael Moore of his latest film, Where to Invade Next?

In fact, I get chatty Michael Moore. “I haven’t done a whole lot of interviews for this film,” he explains. He got pneumonia and was in intensive care when he should have been touring the nation’s chatshow sofas and, unusually, he genuinely seems to enjoy answering my questions. Within minutes, he’s roaming on to Bernie Sanders, a long-time friend of his, and Donald Trump, an old adversary, and although in recent years he’s suffered ill health, the death of his father and divorce from his wife of 22 years, he sounds as if he’s up for the next fight.

And there’s always a fight with Moore. His politics were forged in Flint, Michigan, where his father was a car worker in a town of car workers, and it was where he made his first film, Roger & Me, about the devastating impact of General Motors’ decision to shift jobs overseas. He’s gone on to make films about America’s healthcare system, Sicko, and the financial crisis, Capitalism: A Love Story, and, most notably, about 9/11, George W Bush, and the road to war, Fahrenheit 9/11. That became not just the highest grossing documentary of all time but crowned him as America’s most divisive film-maker.

But there’s been a six-year gap since his last documentary and Where to Invade Next feels like a return to some of his earlier work. There’s less brow-beating, more laughs. He roams Europe looking at things other countries do differently and “claiming” them for America. He visits maximum-security prisons in Norway where the guards have made a pop video of a Michael Jackson song to welcome new inmates, has a four-course school dinner in France and learns that in Italy, on top of eight weeks’ holiday, workers get two weeks’ paid leave to go on honeymoon.

I enjoyed the film but I had no idea what to expect. You’re not really invading other countries, are you? You’re just visiting them and nicking their best ideas. Is the title deliberately a bit misleading?

Yes, I’m also satirically commenting on the fact that when we visit other countries, it tends to be in a tank or a bomber. I wanted to ask: what if we were to visit these countries or, in the American terminology, “invade” them, in more typical ways and do things that might actually benefit us as a people? It’s a bit risky because people may come to the film thinking: “Oh, he’s going to tell us what the Pentagon is up to.” But it’s also because for 25-plus years, people have said: “You point out all these things that are wrong but you rarely have any solutions.” Now, I think you’re doing your job as a journalist or film-maker if you’re pointing out things that are wrong but a mischievous part of me was like: “OK, what if I gave them two hours of no problems, all solutions?”

The poster for Fahrenheit 9/11, the highest-grossing documentary film ever made.

Yes, I thought it was going to be about the military industrial complex and instead it was straight into sex-education lessons in French schools. It was much more joyful than I was expecting.

Well, it’s joyful in that sense, yes, because it’s wonderful to think about sex-ed classes that encourage our young people to enjoy this wonderful gift that nature has given us instead of writing on the blackboard: “Sex equals death”, which is what happens here. If you were watching this with an American audience, you can hear it get very quiet, then you hear sniffles. At various points, people are crying.

It felt different in tone to some of your more recent work… lighter, happier even.

No, it’s just the opposite. It’s my angriest film. But what you’ve said makes me feel very good because you’ve proven my point. Our angriest comedians are best when they’re the funniest. Charlie Chaplin was an angry man. Richard Pryor was an angry man. It actually helps the comedy. I think it’s lighter only in the sense that I have channelled the anger into a place where it reaches a lot more people than just being angry.

It also felt like a very personal film. It almost seemed like a career retrospective in that it touched on lots of themes and issues that you seem to have thought about for a long time. Is that the case?

Yes. I don’t know if retrospective is the right word but yes, I think so. In the months leading up to it, my father passed away and four months after that I got divorced. I think that when you have events like that in your life, you are brought to a place where you are kind of looking back and considering the whole shebang. Right?

It put you in a more reflective space?

Yes, I think so. Though I knew my dad was going to die for probably a year or so earlier and obviously I knew that the marriage was over but I thought those things would lead to the reflective state we often find ourselves in when those big events happen in our lives, which is you go quiet, you are sad, you get depressed, you just want to be by yourself for a while. That didn’t happen. It was actually… I don’t know how to say this. I wanted my dad to live forever but then when he was gone it was kind of like: “OK, let’s live!”

Did some of that spirit manifest itself in the film?

I think so. When I watch it, I see it. I also see the fun that I was having making it. If you talk to any of the crew – who have been with me for 20 years – they will tell you we had the most fun making this film than any other film. Both in the shooting of it but also in postproduction. You don’t know what you’re going to find. I didn’t know the Italians are going to tell me that their fucking honeymoon is being paid for! The look on my face when they tell me that, that “what the fuck?” look on my face is real because we didn’t research this film. We didn’t spend months in preproduction. We spent three weeks looking up a few things. We just decided to keep ourselves open to whatever we found.

Did you know how it would end? In the film, you go to Berlin and reminisce about how you were there in 1989 with your friend Rod, chipping at the wall. And you say this is what makes you an optimist because you had thought the Berlin Wall would be there forever, and then it wasn’t and it’s this that makes you believe change is possible. Had you thought about that beforehand?

No, not at all. We were filming other things in Germany and because Rod was with me and we’d been there 25 years ago in the week that people started chipping away at the wall, we went over there with just one camera to film. We just thought we’d make something for the kids and grandkids. It was not intended at all for the film. It was when we’re in the editing room later and we’re watching all this footage and it seemed that in country after country, people would say to us: “Well, actually this was an American idea and you gave up on it. You gave up on progressive education, you gave up on May Day.” You know, May Day [International Workers’ Day] started in Chicago. And then looking at the footage of the Berlin Wall, it just sort of hit me.

Moore and producer Kathleen Glynn, whom he recently divorced after 22 years, at the Cannes festival in 2004. Photograph: Boris Horvat/AFP/Getty Images

You call yourself a crazy optimist. Do you really feel that about the future of the US right now?

I live in a country with a black president. I don’t know where you live but if you’re in London, you have a Muslim mayor. Of course things get better. Of course things change. Sometimes, it’s two steps forward and one step backward but generally the good guys win and the bad guys lose. The supreme court, dominated by Republicans, voted to eliminate marriage discrimination and allow people here to marry the person that they’re in love with. I never thought I’d see that in my lifetime.

It’s noticeable that you didn’t invade Britain in this film. Was there anything that you considered taking from us?

It’s just a little obvious, isn’t it?

Is it? It felt like a lot of the things you were looking at in other countries are things that we had in Britain until recently but that have now gone, things like free university education.

Yes, I meant obvious in that it would obviously be easier for us to go to a country that speaks the same language. It was a conscious decision to ignore the UK because of the way your country has drifted in the last decade or so. It’s been disappointing to those of us who admire a lot of what the British have done. Many of us believe Tony Blair was worse than Bush because Bush we expected. And then, the thing that so-called New Labour did to try and unravel the social safety net in Britain. It’s sad how like us you are becoming.

What do you think has been most surprising to an American audience? Was it American students going to Slovenia to study for free? Or was it the Italians saying they have eight weeks’ paid holidays?

I’ve watched the audiences in the US and they sit with their jaws agape for most of the film because they can’t believe what they’re hearing. When we show the prison guards singing We Are the World in Norway. They’re just like: “You’ve got to be kidding me.” But there’s something even more complex to an American audience, which is the concept of “we” as opposed to “me”. In this country, we believe that I’ve got my problems and you’ve got your problems. And if I end up with more slices of the pie than you, tough shit.

At the centre of the film, you suggest that Germany has come to terms with its history in a way the US hasn’t. Do you see many of America’s problems as a consequence of not facing up to its past?

Yes, isn’t it step one of the 12-step programme? The very first thing you have to do is acknowledge you’ve got a problem. Unless we’re willing to do that, we’re going to have a hard time making some of the social changes we need to. If black Americans who’ve been on the bottom rung of the ladder remain on that bottom rung, to this day some 160 years after slavery, I think we need to address that. Every other group that has come into this country, be they Asian, Arab, Jewish, Irish, Italian, everybody starts off at that bottom rung of the ladder and has been able to come off that rung. Everyone except Native Americans and African Americans.

Moore in his 2007 film Sicko, which painted a rather rosy picture of the state of the NHS, in a contrast with the US health system. Photograph: Lionsgate

You say you’re an optimist, but doesn’t gun control give you cause to feel depressed? Bowling for Columbine was so powerful on the subject, yet the situation is far worse today than when you made the film.

I’ve seen many things get better except for the one thing that you have just mentioned and it has only gotten worse. There’s now at least one mass shooting a day in this country. That means four or more people being shot. Obama has wanted the Center for Disease Control to study this gun-violence problem as an epidemic but Congress has blocked it.

As I pointed out in the film, the Canadians have a lot of guns and they do not kill each other at the rate we do. Their kids are watching the same violent movies and they have the same divorce rate, broken homes, all that crap. Why us and not the Canadians? I think it goes back to we are a frightened people. Why are there 300m guns in our homes? The reason you have a gun is because you’re afraid. What are you afraid of? You’ve been lied to.

Tell me about Bernie. You’ve known him a long time, haven’t you?

Yes, I campaigned for him in 1990 when he first ran for Congress.

Why has his time suddenly come? He’s been saying this stuff for decades. Why are people willing to listen to him now?

Can I take some of the credit for it? Two generations of young people have gone through school watching my films, shown to them by their teachers. I get mail every day from high-school students who see my films in class. And I’m part of a generation that raised these kids. We’re leaving them with a warmer planet, with a lot of problems. But one thing we gave them is that we taught them to love. These kids are not haters. This younger generation do not hate you for the colour of your skin, they do not hate you because you’re in love with someone of the same gender. That’s the best thing that we did. When the Merriam-Webster dictionary announced in December the most looked-up word for 2015 online, it was “socialism”. That’s what we did. We raised them with a basic belief that everyone deserves a seat at the table and that everyone must have a slice of the pie.

So, do you think we will see President Sanders?

Listen, I think anything can happen in the next two to four months. Seriously. If I’d said to you a year ago, I think there’s a chance Trump could be the next president, I would have sounded like an insane man. But in this election year, I think anything can happen. In every public opinion poll, Bernie beats Trump by many more points than Hillary does. I think the Democrats, by the time of the convention, are going to have to decide – do they want to win or not?

Can you explain Donald Trump to a European?

I’m thinking how to put this… I’m sure you’ve noticed Americans are very alpha. Like, we’re number one! We’re number one! We’re the best! Trump is that on steroids. And it’s a tune that Americans like to listen to. Not all Americans, not the majority, but this isn’t going to be an election about the majority. It’s about who’s going to vote. We have a country where we try very hard to get 50% of the people to vote. You have to remember, 80% of this country is either female, people of colour or young adults between the ages of 18 and 35. He has offended all three of these groups to such a large degree there’s no way he could win a majority of women, blacks, Hispanics or young people. That’s off the table. But he can win if the other side stays home, and let me tell you something, nobody is going to be excited to get up that morning and vote for Hillary Clinton, even if you like her. She does not inspire that in people. Trump, on the other hand, inspires his side. It’s like Munich in 1932.

Winning the 2003 Oscar for best documentary for Bowling for Columbine. Photograph: Rex

Is it? Is it fascism?

It is fascism, of course it is. Absolutely. Yes. He wants to combine the power of capital with the power of the state and to use the “other” to drive a huge amount of fear into people’s hearts. That’s working well with the 19%, that’s all that’s left of white men in America over the age of 35. The country’s changing but they are not going to go quietly and that’s why you see how big and how angry the whole thing is. I have told people to take it very seriously. Look, of course, he’s a clown. He’s a performance artist. He’s a buffoon. He’s all these things.

The Economist, in its review of Where to Invade Next, said: “Smug leftwingers will like it because it reinforces what they already know, but middle Americans will recoil from the racist, violent picture of their country that it paints.” What do you think of that?

I’ll say it again, the majority of Americans are women, people of colour and young people. The majority of people who entered school in September were not white. The mythological figure of the American, perfectly embodied in Donald Trump, is no longer the American.

To change track slightly, you were born and raised in Flint, Michigan, an automotive town, and you started your film-making career with Roger & Me, a documentary about job losses there. You’ve recently been involved in another campaign in Flint for clean water. Does it feel like you’ve come full circle?

It was never a circle, because Flint never got better. It’s gotten worse and worse and worse. People in Flint look at my first film now and wish they lived in that Flint. That Flint still had 50,000 General Motors jobs when we made the movie. Now there’s 5,000. The governor wanted to give the rich a billion-dollar tax cut and in order to do that, he had to cut services. So he took the people of Flint off the clean water from the Great Lakes and made them drink from the Flint river, which is essentially a sewage ditch. And because the people of Flint have no power, majority black, majority poor, they knew they could get away with it. And when it was discovered the people were drinking lead because of corrosive water from the sewage ditch, it was covered up. It’s just awful. If I were to do a psychological study on myself, I think I’d find that at the core of everything is Flint.

I did this story recently about how the acting profession in Britain has become very middle class. Is it your experience that there are not very many people making films who come from a place like Flint?

Yes. And I don’t mean to offend people in the UK, but it’s just another example of how you are turning into us. I’ve been watching a lot of films the last couple weeks because I have a film festival and I’m thinking: “Is there something else I could have done?” Because the voice of the voiceless, the voice of the people that come from Flint, Michigan… where are they? Where are they? We used to live in a time where if you came from Brooklyn, you could become Arthur Miller. Where something artistically huge could come from a place like Liverpool.

When the film was launched in the US, you were supposed to be going on a massive publicity blitz, but got very bad pneumonia and ended up in intensive care. Has that made you reflect upon your own mortality?

Yes. Ten days in the ICU [intensive care unit] will make anybody reflect on their own mortality. Every day people are being wheeled out dead. The fact that it happened two weeks before the US release was very disappointing to me, because I couldn’t do anything to help the film, but it’s still the largest grossing American documentary this year.

Has your brush with death made you reassess what you’ll do next?

Yes. More comedy. I don’t talk about what I’m doing next but it will be different.

One of the things that struck me in your film was where you interview the prosecutor in Iceland who, after the financial crash, went around arresting bankers. It really felt to me like this was something that was very dear to your heart. You were practically gleeful at the idea of doing that in America.

Yes, I don’t just want to take that back to America, I’d like that job. If I could get hired to do that job, I would quit film-making for a while and after I’d put about 60 or 70 of these hedge-fund bankers in jail, then I’d go back to making some movies. Gleeful. You’re the only one that’s mentioned that! But it’s so true.

Where to Invade Next is released in the UK on 10 June. Michael Moore will be in conversation with Owen Jones after the premiere at Sheffield Doc/Fest. The event will be broadcast live via satellite to 125 cinemas in the UK and Ireland. Find your nearest screening at wheretoinvadenext.co.uk/screenings