Roland Emmerich, director and co-writer

Me and Dean Devlin wrote the script. I had an office right next to Book Soup on Sunset, and I went in there and bought the classics like War of the Worlds but they were all too old-fashioned. We were fans of disaster films, but there hadn’t been one for a long time – in the 70s they had made a disaster out of anything, like a swarm of bees. But aliens were a new idea. We both lived in the Hollywood hills, and I took Dean to the window, and said: imagine if all this sky was the underbelly of a ship. We thought: OK, that’s cool.

There is no one more American than Will Smith

I told our agent we wanted to do it, and he said forget about it, Tim Burton is doing Mars Attacks! I said to Dean, we can’t do our film after a parody comes out. We had to beat him to it. If it came out on the 4 July weekend, we would beat Mars Attacks!, which was coming out in August. So we wrote the concept around the release date. Dean said: “Let’s just call it Independence Day; we can come up with something better later.”

Will Smith’s role was not written as black; his ethnicity was not mentioned, so the studio assumed we wanted to hire a white guy. But we set our sights on Will very early. There is no one more American than Will Smith. The studio had a problem with it as he was mainly known for sitcom, but they came round to it.

Saving the world as a team … Will Smith and Jeff Goldblum go into battle Photograph: Moviestore/Rex/Shutterstock

We were decorating the set and I was like, guys, there’s too many flags. And they all said, no, this is the fourth of July! Then when it came out, the whole world thought I was Mr Superpatriot. But what no one saw was this was an African American, a Jewish man, and a white-bread politician saving the world as a team. Then my next film was The Patriot. But politically I was always more on the left, and I felt concerned about that. So I did The Day After Tomorrow, which criticised America quite a bit.

Just after Independence Day came out, I met Steven Spielberg and he said: “What you guys have done with that film, everybody will imitate you.” He was right. When you look at Marvel movies today, it’s always about alien invasion, and a lot of stuff gets broken. Also, these films don’t take themselves too seriously. But I had learned this from Back to the Future and Raiders of the Lost Ark.

I don’t believe in aliens but I really hope they are out there. “The question of whether we’re alone in the universe has been answered” – that was a line that came from me. Finally, they’re out there – in very big ships!

Is it a comedy? … Bill Pullman, centre, as President Whitmore in Independence Day Photograph: Roland Grant Archive

Bill Pullman, actor

I got a call from my agent saying they’re interested in you for a Fox movie, as a president. I said: is it a comedy? Because that would make sense. At that point, there weren’t movies that had a president as a lead character, unless it was a biopic, and then usually only on television.

I really enjoyed working with Roland. He’s always aware of what would be “cool” – the way he uses that word, with a German accent, reminds me of the teenager in him. “Then you look up and you see this really cool monster...” I was also impressed with the presidential cufflinks – I think they got them from the gift store of Nixon’s presidential library. They were talismans: I could touch them, and remember: oh yeah, I’m the president.

We shot the ending of the movie first, where I come up to Jeff Goldblum, and we’re overcoming this long history. It was absurd, having these warm embraces with people we barely knew. I had to shake a little giggle out of me.

In the scene where I go into Area 51 and see what they’ve been doing without my knowledge, Will Smith comes in, and it’s the only scene I have with him. It was when the verdict for the OJ Simpson trial was announced; everybody was glued to the TV in their trailers. We got to the set and Will said: “OK, I see I’m here with a lot of angry white people!” It was perfect.

Fox was interested in a different title to Independence Day. Dean and Roland said: we’ve got to move up the filming of the rousing speech scene, because in that you understand why the movie is called Independence Day. I was influenced by hearing Robert Kennedy’s speech after he had just found out Martin Luther King had been killed – you knew he wasn’t going from notes. A day or two later I watched it, and I thought, holy fuck, this is good. They’re going to keep the title!

It’s a fable, and there are coincidences that happen in a fable that you have to just let go of. It’s a good movie, but you wouldn’t say it fits all the rules of profound movie-making. Characters run across each other in dire circumstances and you’re like: really? They found each other there? But it has a bravura about it. We’re just going to tell a fun story, and you’re going to have to ride with it.