ACTRESS Joan Allen glides into the interview, all poised and immaculate.

As one of the two steely females playing off a gritty Matt Damon in Paul
Greengrass' latest action flick, The Bourne Ultimatum, she is as collected as
her CIA chief Pamela Landy.

Easing herself noiselessly into a sofa at the Claridge's Hotel, she sits
upright like a dancer in the caress of delicate lace, carefully dispensing her
words with an ethical knowingness that seems to be as much her personal charm
as it is of her screen character.

"Pamela's getting more information about Jason Bourne; she's trying to get to
the bottom of things," Allen, 51, says.

"She's not too sure about the new CIA mandate, which is to shoot first and ask
questions later. Eventually, she makes a very bold choice, which is ultimately
a very courageous thing to do."

Never-ending arms in a diaphanous shroud, sending forth her words with
gesticulations carved out from the grace of ballet extensions, the Rochelle,
Illinois-born actress is steady to the hilt.

Over a list of cinema appearances that have gained Oscar and Golden Globe
nominations - a conscience-racked adulteress in Yes (2004), a presidential
candidate in The Contender (2000), an emancipated housewife in Pleasantville
(1998) - the industry has come to cast her, in her own words, as "the moral
centre of films".

"I suppose it's in my midwestern roots," says the daughter of a gas-station
owner and housewife, who took up acting to overcome an early shyness. "But it's
so hard to see yourself from the outside, to see how people perceive you. Maybe
it's a sense of what I project. Or how my parents taught us how important it
was to be doing the right thing, to be an honest person."

Allen is correctness personified. This is not of a conservative
goody-two-shoed-ness, but an unwavering determination that is almost male.

In person, during a 15-minute interview, the only hint of feminine frivolity
betrayed by a flawless face apparently free of make-up is a pale lipstick stain
on her flask of chai latte - "I don't take coffee, this is my preferred drink".

In preparation for her role, she called up old school friends to set up
meetings with real CIA women, "entering a world I never would have been able
to".

Yet even as she oozes tenacity on film with a professional actor's elan, she
acknowledges that she would "absolutely never be able to live the life of a
real agent".

"It's manipulative, getting people in effect to betray themselves, to tell you
secrets," she says.

"You have to be so convinced of the greater needs of your country, of the
goodness in your political administration, to maintain such a seeming
ambivalence about it all."

The words carry just a little more meaning: Allen admits openly to being a
card-carrying liberal who has been watching the rise of Barack Obama and Hilary
Clinton in the upcoming American elections with hope and restlessness.

"It's interesting," she says. "With both of them in the run, it's as if the
Democrats have everything given to them on a silver platter."

Beyond such an open endorsement, however, the actress is more coy about her
personal moral codes. She counters: "I'm actually quite private.

"I don't know why...," she trails off, looking away to think. "Perhaps it's
just one of those things that I've been brought up not to talk about - like
your bank account details. Or religion."

It all fits together, you think, as you later find out about the actress'
dedication to her profession in terms of purposefully living out alternative
existences within a contained environment.

"Acting provides a safe platform on which one can be very expressive, except
that it's not for real. A lot of actors are very introspective people," she
says.

"I've always been able to make that kind of separation in my mind, between the
roles and myself. There's no blur."

She talks about her professional life, but is guarded about most else. There is
no mention of her teenage daughter, Sadie, from her marriage to actor Peter
Friedman. She is now divorced.

In the spirit of a somewhat shocking recklessness, however, she allows you to
peek at the label of her distractingly lacy blouse to ascertain that it is one
of her favourite designers, Catherine Malandrino.

The little escapade sends a PR executive into a gasp of horror.

She gestures that time is up.

Her wiry arm leans out in a willowy handshake. As she slowly rises, unfurling
her perfectly splayed limbs into a plie of a goodbye greeting, you suddenly
realise that she is thin. Very thin.

"I think part of it has to do with the genes," the actress admits. "But also
I'm a gym rat. It used to be six days a week. But I've started to walk now
instead. Thirty blocks a day in New York City where I live."

The Bourne Ultimatum is playing in cinemas.