"My wife is considerably younger than I am," George Clooney tells me, as if I might somehow have missed the fact that in 2014 he married Amal Alamuddin, a human rights barrister 17 years his junior. "And I will say: 'Oh, you've got to see this film. It's one of the greatest you'll ever see.' And so we go and watch it and it's terrible."
Clooney shrugs. "Almost all entertainment means something different in different times. The sensibilities of the day are sometimes what date films and television shows, and sometimes what make them more prescient."
For Clooney, Catch-22, Joseph Heller's 1961 anti-war satire, is a case in point. "It's a classic because the basic tenets remain: s*** rolls downhill; authority is to be made fun of; war is insane. This story would play just as well in Ancient Rome as it would 50 years in the future."
In 1970, Mike Nichols followed up The Graduate with a big-screen adaptation of Heller's novel, starring Art Garfunkel and Jon Voight. It was described by critic Vincent Canby, of The New York Times, as "the best American film I've seen this year". Almost 50 years later, Clooney is having another shot at it, producing and directing a six-part version for television that stars Christopher Abbott, Kyle Chandler and Hugh Laurie. Clooney also appears in two episodes as the shouty, short-tempered Lieutenant Scheisskopf, a character absent from the earlier film. It's Clooney's first return to the small screen since leaving ER, the long-running hospital drama that launched his career, 20 years ago.
We are talking at a corner table in a hotel in Pasadena, California, beneath lighting that might have been designed for an interrogation. Dressed in a dark grey suit and open-necked black shirt, the 58-year-old star looks trim and tanned and, despite the unflattering light, as ridiculously handsome as he does on screen.
He's the first to admit to being daunted by the prospect of taking on Catch-22. "The one thing stopping us jumping immediately was that it is one of the greatest American novels of all time," he says. It is also difficult to adapt, with a structure that screenwriter Luke Davies describes as "chaotic, kaleidoscopic madness". But, says Clooney, "you have to take a swing and hope you hit the ball along the way. I've been lucky in my career – there have been some things that have been fun and easy, but then you go, 'Whats the next level?' You want to take some chances, take some risks."
War is a subject that Clooney has tackled before, not least in one of his earliest successes, David O Russell's Iraq-set drama Three Kings (1999). But he felt a more personal connection to the Second World War setting of Catch-22. "My uncle was a B-17 bomber pilot, and I have his card at home, with all his bombing missions written on it, including Dresden," he says. "He was 17 when he enlisted, 18 when he was flying. When they call that 'the greatest generation', they're not wrong."
Quite aside from defeating the rise of nationalism, he believes that the Second World War also triggered a revolution in American culture. "We sent millions of people overseas, and we didn't just fight a war, we learnt about culture, we learnt about food and art and music, and skiing. Then they came home and it changed our country, made it so much better," he sighs. "The next couple of generations travelled less and less. I think in 1990 less than 10 per cent of Americans had passports" – according to the BBC, the figure was as low as 4 per cent – "and when you don't travel, you are afraid of what's out there. When you don't travel, you can so easily cast other people as the enemy. You can be made to believe that all refugees are terrorists."
Clooney, long the liberal face of Hollywood, has used his star power to raise awareness of countless international issues, including the Armenian genocide and the conflict in Darfur. Earlier this year, he called for a boycott of the Dorchester Collection hotel group, owned by the Sultan of Brunei, in protest at the ruler's outlawing of homosexuality and adultery, now punishable by death by stoning.
Since marrying Amal, Clooney has all but abandoned Los Angeles, his home of more than 35 years, and now spends much of his time at the couple's British digs, a substantial pile on the banks of the Thames at Sonning, Berkshire, with its own mooring, swimming pool and private cinema. I ask if he finds it easier to maintain a private existence over here. "I don't find it easy to have a private existence anywhere," he says. "The paparazzi are outside the house all the time. You're always aware of it."
He and Amal have gone to great lengths to protect the privacy of their twins, Alexander and Ella, who turned two on Thursday, even threatening to sue a French magazine over pictures published after a photographer scaled hedges surrounding their property. Today, however, I have barely taken my seat when Clooney whips out his phone and says, "Can I show you something fun? My wife just sent me this." On his screen is a shot of the twins, in high chairs, wearing most of their lunch. He zooms in on Alexander's face, then scrolls to a picture of another small boy, this time in black and white. He is a carbon copy of Alexander. "That's me," says Clooney, beaming. "Except my picture looks like it's from The Grapes of Wrath."
As a child, Clooney had no intention of becoming an actor. "I thought I was going to go into broadcast journalism," he says, "because that's what my father did" (Nick Clooney, 85, is a former television host and anchorman). But after dropping out of university, and taking a variety of jobs – from selling insurance and women's shoes door-to-door, to harvesting tobacco – he signed up to acting classes. There he met Grant Heslov who, 36 years later, remains a close friend and collaborator; Heslov directs two episodes of Catch-22.
While he never worked in journalism, Clooney still holds strong opinions about the media. "I believe in the freedom of the press," he insists, "even when it bothers my privacy." Earlier in the day, however, speaking at the Television Critics of America conference, he deplored the way in which the Duchess of Sussex, then pregnant, was being "pursued and vilified" by the press, and likened her treatment to that of Diana, Princess of Wales. "It's history repeating itself," he said, ominously. "And we've seen how that ends."
He returns to the topic again now. The Duke and Duchess of Sussex are, he says, "friends of ours. And the public likes her, she is very popular. But the tabloids have decided that they get clicks and sales by doing this. The kind of hatred and vitriol [directed towards the Duchess] is exactly reminiscent of Diana. Everyone was devastated after the tragedy, and that lasted a couple of months, and then everyone was right back doing it again.
"Amal and I get it the whole time," he continues. He's no longer surprised to open a paper and find a piece speculating, "that we're breaking up, that our marriage is over. And then when we go out to dinner and they take pictures, it's: 'Oh, they're trying to reconcile their marriage!'"
Such is the price of fame, some might say, the downside to being, as Time magazine once called him, "The Last Movie Star". For Clooney, the kind of roles that earned him that tag – in Batman & Robin, Out of Sight, Ocean's Eleven – now appear to be in the rear-view mirror. "I've had a lot of offers to do big studio pictures," he says. "But the worst you can do is hang on to things long after your due date."
He breaks out another grin. "And here's the thing: I sold a tequila company. I don't need money." No kidding. According to Forbes, last year he earned $236 million before taxes – thanks, in no small part, to the $1 billion sale of Casamigos, which he founded with Rande Gerber – making him the highest-paid actor in the world. His annual pay packet exceeded that earned by the top 10 actresses combined.
Which brings us, inevitably, to the subject of gender inequality in Hollywood. Clooney holds his head in his hands. "When everything broke, we were already working on Catch-22, and I was like, 'Oh god, it's all men,'" he grimaces. "But it's 1944, it's war, and you can't suddenly make [the characters] all women. It's not Ocean's 8." So Clooney – who was originally slated to direct four of the six episodes – came up with another way to address the inequality. "I called the producers, and said: 'Give two of my episodes to Ellen Kuras'." And that's how Kuras, the series's cinematographer, found herself in the director's chair.
As the new series reaches British screens, Clooney's mind is turning to his next project, an eight-part drama about the Watergate scandal. The topic could hardly feel more timely.
"You look at the characters from that – Bob Haldeman, John Mitchell, John Ehrlichman, John Dean, Charles Colson," he says, referring, respectively, to Nixon's chief of staff, attorney general, chief of domestic affairs, presidential counsel and special counsel. "They were all pretty talented, intelligent guys and they all went to jail." He cocks an eyebrow. "We certainly think it's an interesting time to talk about those things."