"Salt" is a very silly movie, and by the end of its brisk and breathless running time (and I mean that literally), it makes the "Bourne" movies look like documentaries.
I'm not entirely sure that's a bad thing.
Angelina Jolie is, in my opinion, a casting problem in anything at this point, and it's simply a side effect of her megafame. She projects such a powerful, fully-formed persona that it is difficult to accept her vanishing into a role. She's a talented actress, she works hard in her films, and I feel like no one could ask more of her than she already gives for her movies... but that hesitation on my part remains. You watch her onscreen, and it's Angelina Jolie, no matter what.
Part of it is the way she looks, sure. She's a cartoon, a comic-book artist's idea of the dangerous bad girl. Because she is so visually extreme, I don't buy her as, say, a spy or someone who is meant to be anonymous or adaptable. I still think the notion of the "little grey man" is the most potent notion of who a spy should be, someone you wouldn't look at twice. No matter if she's wearing long blonde hair or a dyed Morticia Addams do, Jolie stands out in any crowd.
But part of it is that there is some part of her as a performer that feels unbending, like she can't submerge her own personality enough anymore to convince as someone else. That actually serves "Salt" to some degree, because the character she plays, Evelyn Salt, is living several different roles at once, with a central core that remains unchanged no matter what situation she's in. That's a gift in the film's opening moments, where we see her in North Korea. She's been captured, and she's being tortured in an effort to convince her to confess that she's working as a spy. She keeps denying it, over and over, her cries becoming more pathetic as the main title is revealed and we cut forward in time to her release. She's being traded for a North Korean who ended up in the hands of America, at the insistence of her boyfriend Mike (August Diehl), who has no idea what she does for a living.