Scarlett Johansson's curious career is at a crossroads

Scarlett Johansson has become one of the biggest, most bankable female stars on the planet. She is undeniably a sex symbol -- any Google image search finds virtually nothing but pictures of her in some state of undress -- but she is also politically engaged and seemingly pretty affable.

That said, she doesn't have a definitive star persona.

At 32, by Hollywood's sexist standards, she is entering this strange period where the industry typically starts to marginalize women.

Despite being a happily married mom now, she is still an object of desire for male moviegoers, and her latest Ghost In The Shell, has her in yet another skintight outfit dispatching bad guys with highflying kicks and gunfire, not unlike she did in the hit movie Lucy.

Curiously, she has never been even nominated for an Academy Award. She has never, for the most part, done a role to downplay her beauty in a bid for prestige. She has never quite shown tremendous range, although she has dabbled in quirkier less mainstream fare, such as her voice-only role in Her and her truly underrated, largely silent performance in Under the Skin.

I remember first encountering her in Ghost World, where she is actually the sidekick of the lead character played by Thora Birch. Her real breakthrough was in 2003's Lost In Translation, where she held her own opposite Bill Murray in arguably his career-best performance. Even in that film, the opening shot is a close-up of her buttocks, and whether this has been intentional or not, she has often been portrayed as an object first and a character second.

Scarlett Johansson in Under the Skin

After the success of that film, Johansson seemed ubiquitous at the movies, many of which weren't particularly memorable. The two standouts for me were a pair of Woody Allen films. Johansson was briefly labeled his new muse in the press, and their partnership yielded two of the best movies of both their careers Match Point and Vicky Christina Barcelona.

In both films, Johansson plays a fiercely intelligent, sexy woman who is also vulnerable, moody and needy. She is both believable and charismatic in both, and I think both hint at what a compelling actress she is capable of being when a director gives her more to work with.

Now, she is fine and fun in the Avengers and Captain America movies, but until she gets a standalone film as the butt-kicking Natasha Romanoff (and all indications are that she won't), the character will always feel like a marginal one within the greater universe of those movies.

Which brings me back to Under the Skin, one of my favorite films of 2013 and one of my wife's favorite films of all time. Part of what made that film such a stunner was Johansson's uncharacteristic performance. Its slow paced and open-to-interpretation script probably doomed its chances of ever being a big commercial hit, but sadly almost all the publicity the film received was surrounding the fact that it was the first movie in which Johansson would appear nude.

That's a real shame, because the film presented some really interesting new directions for Johansson's career. I am a fan and I generally enjoy her movies, but I'd love to see her make more artistically risky movies, where she undermines her image or at least plays against it.

I think right now she is at a crossroads. She has proven she can deliver at the box office and now the true test of her enduring starpower is whether she has the acting gravitas to challenge and surprise audiences on a consistent basis. I'm rooting for her.