His biopic of Che Guevara recouped half its budget and his Brad Pitt-starring baseball film was pulled five days before the shoot began. The director of Traffic and Erin Brockovich tells Henry Barnes why he might just disappear

Steven Soderbergh doesn't sound fine. A bad telephone line between London and Los Angeles isn't helping, but it's not wholly to blame for his air of tired resignation. That crept into his voice as soon as he started talking about Che, his two-part, four-and-a-half-hour-long biopic of Ernesto Guevara.

"Everybody got scarred by [Che] a little bit," Soderbergh says. "I don't know how to describe it. It took a long time to shake off. It was just such an intense four or five months that it really … "

There is a long pause. He speaks slowly and evenly.

"You know, for a year after we finished shooting I would still wake up in the morning thinking, 'Thank God I'm not shooting that film.'"

Does he wish he hadn't done it?

"Yeah."

Really?

"Yeah. Literally I'd wake up and think, 'At least I'm not doing that today.'"

Soderbergh knew Che (recently released on DVD in the UK) might be difficult from the start. The project was brought to him by its eventual star, Benicio del Toro, and producer Laura Bickford, during the shooting of Traffic – the drug war drama that won Soderbergh the best director Oscar in 2001. Che was essentially Del Toro's baby and Soderbergh, who was interested in the man but nowhere near as smitten as the actor, approached the movie cautiously, heading into the production with what he describes now as a "pretty significant sense of dread".

Lack of funding fuelled his fear. And the money wasn't there partly because of Soderbergh himself. In the characteristically noble pursuit of authenticity he decided to film Che in Spanish, a decision that effectively blitzed any hope of finding significant investment within the US.

"It's a film that, to some extent, needs the support of people who write about films," he argues. "If you'd had all these guys running around talking in accented English you'd [have got] your head taken off."

Eventually European investors were tapped for $58m (£35m) – a paltry figure considering the project's ambition. As a result Soderbergh was forced to shoot extremely quickly to stay on budget. The two parts were filmed over 76 days, four days fewer than for his glitzy Vegas action comedy Ocean's Eleven, an $85m capitalist fat-cat of a movie in comparison with Che.

"It's hard to watch it and not to wish we'd had more time," he says of Che. "But I can't tell you that if we'd had more time it would be better – it would just be different. There was an energy and intensity that came out of working that quickly."

Indeed, Che is easily Soderbergh's best film since Traffic. But it wasn't a resounding smash at the box office, grossing about $30m worldwide. Soderbergh blames piracy ("We got crushed in South America. We came out in Spain in September of last year and it was everywhere within a matter of days. It killed it.") but it probably didn't help that his film is a foreign-language marathon with an admittedly distant and impersonal lead.

Che seems, in retrospect, like a glorious, sad aberration: a niche-audience epic it would be impossible to commission in these straitened times. Today, the willingness of the studios to take such a punt has all but evaporated – a fact that Soderbergh is more alive to than most.

"I'm looking at the landscape and I'm thinking, 'Hmmm, I don't know. A few more years maybe,'" says Soderbergh. "And then the stuff that I'm interested in is only going to be of interest to me."

It would all sound depressing if Soderbergh didn't pepper his speech with fits of incredulous laughter. Perhaps the last few years – capped by his recent run-in with Sony over his revised script for Moneyball, a baseball movie starring Brad Pitt, that saw him elbowed off the project – have left him punch-drunk.

"In terms of my career, I can see the end of it," he says. "I've had that sensation for a few years now. And so I've got a list of stuff that I want to do – that I hope I can do – and once that's all finished I may just disappear."

The list isn't that long. Already completed are lo-fi relationship drama The Girlfriend Experience, followed by the breezy Matt Damon comedy, The Informant! After that there's another biopic – Michael Douglas as Liberace; a rock musical of Cleopatra with Douglas's wife, Catherine Zeta-Jones, and his long-gestating adaptation of John Barth's picaresque novel, The Sot-Weed Factor. "Three or four years worth of stuff," says Soderbergh.

It's said with resignation, not desperation. With the voice of someone who has gradually realised what Guevara might not have – that some systems are just too big to beat.

• Che: Parts One and Two are available on DVD and Blu-ray now