Cover Story: Sienna Miller On Vogue

VogueSienna Miller's next two projects couldn't be more different. This summer the 27-year-old stars as the villain Baroness in the popcorn flick "G.I. Joe: The Rise of Cobra" before making her Broadway debut in "After Miss Julie." Sienna talks about these polar opposite roles and her tumultuous love life in the pages of this month's Vogue (see the full cover after the jump).

"G.I. Joe" marks Sienna's first foray into big-budget action fare, and she admits to being apprehensive about the large-scale production. "It was so out of my comfort zone," she said. "Everything gadget-wise that I had to use actually worked. I had these little guns, and if I fired them, lights came up and they made a sound. It was Disneyland for grown-ups."

Vogue

Though her next role as the titular character in "After Miss Julie" isn't so flashy, that doesn't mean Sienna didn't have reservations about the part. "She's kind of detestable in a lot of ways. That's something I struggle with....She's vulnerable, she's messed up, she's manipulative, she's promiscuous, she's damaged — all of the things I'm supposed to be, according to certain journalists, so I don't know whether I'm being really smart or really stupid."

For Sienna, however, it's often her love life, not her acting abilities, that grab headlines, especially her on-again-off-again relationship with Jude Law. "I talked about him in an interview not long ago, saying that I still love him, and he was like, 'Please stop talking about it.' This was going to be the first interview where I was going to try to be guarded and detached, not give anything away, and actually I realize that it's irrelevant. You have to be yourself...." In fact, the real Sienna's dating life may not be as exciting as everyone makes it out to be. "I've actually never been taken on a date in my whole life," she says. " I have never had a one-night stand. I'm a real relationship person— contrary to public perception."

Are you excited to see Sienna in "G.I. Joe"?