“Charlie Wilson’s War” is that rare Hollywood commodity these days: a smart, sophisticated entertainment for grownups. Based on the late George Crile’s sensational bestseller about how an unlikely trio of influential and colorful characters conspired to generate covert financial and weapons support for the Afghan Mujahideen to defeat the Russians in the 1980s — and armed America’s future enemies in the process — Mike Nichols’ film is snappy, amusing and ruefully ironic. But not even the stellar talent on both sides of the camera may be enough to make these qualities alluring to general audiences or those much under 40, making B.O. prospects a mid-range thing.

Crile’s 2003 book unfolded the full story of exploits little noticed when they happened, a story that once more proves truth can be stranger than fiction, and in this case far more outrageous. Charlie Wilson was a liberal Democratic congressman from East Texas known as “Good Time Charlie” for his swinging-bachelor lifestyle. He had women everywhere (including, as the book points out, the present director’s current wife, Diane Sawyer) and was a big-time boozer, but also possessed a strong knowledge of history and a keen interest in foreign affairs.

Although the narrative begins with Charlie (Tom Hanks) in a Las Vegas hot tub with three naked ladies and another guy — and soon has them all doing coke in a limo — Nichols and screenwriter Aaron Sorkin, who knows a thing or three about Washington, D.C., generally play down Charlie’s more licentious and easily caricatured aspects in favor of his bright, inquisitive and resourceful traits. Charlie is the first to admit his faults, but his most salient talent is as a master operator who can talk to and get along with anyone. Hanks, who in certain ways does not ideally match up with Charlie’s cocky personality and looks, persuasively puts across the crucial smoothness and charm.

Igniting Charlie’s passion for helping the Afghans in the wake of the Soviet Union’s 1979 invasion is Houston socialite Joanne Herring (Julia Roberts), a beauteous and connected power broker who uses her intimacy with Charlie to convince him to do what Congress is unwilling to do: End the Cold War by helping the ragtag Afghan holdouts defeat the Russkies.

Joanne arranges for Charlie to meet Pakistan’s President Zia (a sternly wry Om Puri) in Islamabad, where, despite his faux pas of asking for booze during his audience with a fundamentalist Muslim leader, the ball starts rolling, and the suffering Charlie witnesses during a visit to an Afghan refugee camp turns the fire in his belly to full flame.

There are many stages leading to the point where this good old boy is able to up his government’s unpublicized funding of the anti-Soviet jihad from $5 million to $1 billion per year. But the main objective is getting the Mujahideen weapons to shoot down fearsome Russian helicopter gunships, and, in this endeavor, Charlie receives critical help from maverick CIA op Gust Avrakotos (Philip Seymour Hoffman).

If the movie just glides along amusingly at first while dispensing obligatory exposition, it starts firing on all cylinders once Hoffman shows up. Decked out with a pouffy ’80s hairdo, moustache, protruding gut and ever-present smokes, Hoffman’s Gust moves into a room, plants himself there like an unmovable oak and lets loose with a barrage of delicious verbiage that is equal parts exceptional expertise and withering invective. This reps yet another indelible performance from the amazing Hoffman; whenever he’s on, the picture vibrates with conspiratorial electricity.

Knowing Israel has a limitless stash of Soviet-made weapons (and the CIA may not supply U.S.-made weapons to the Afghans), Gust arranges an unthinkable deal between the Jewish state and Islamic Pakistan, a deal furthered when Charlie brings his own Texas belly dancer to perform for officials in Cairo.

While battling drug charges at home that threaten to send him to prison (a federal case pointedly led by one Rudolph Giuliani), Charlie uses his position on the Defense Appropriation Subcommittee to maneuver cash and kindle support for his cause. When Stinger missiles finally find their way to the Afghan rebels, the tide turns, leading to the Soviet retreat in 1989.

Given the density of the story, the hefty number of characters and the governmental arcania involved — Crile took well over 500 pages to lay it all out — it’s impressive how Nichols and Sorkin have compressed the essentials down to a trim 94 minutes (sans final credits scroll). This is the kind of big Hollywood movie on a big subject with big stars that one would expect to clock in at two hours and 20 minutes. That happens to be what Nichols’ previous political comedy, “Primary Colors,” ran, so it’s possible he learned from that outing, which would likely have benefited from similar brevity.

The pacing of “Charlie’s Wilson’s War” is exceptional. The material provides much to think about and discuss afterward, but Nichols doesn’t pause for reflection while it’s all unfolding onscreen. The tempo and balancing act achieved by the director and editors John Bloom and Antonia Van Drimmelen are virtual perfection.

Some 37 years later, there are interesting echoes here from Nichols’ film version of “Catch-22″ relating to illicit activity by those in government service, absurd juxtapositions, unimaginable eventualities and unofficial history. At the same time, given Nichols’ roots in comic theater, it’s no surprise that the funniest scene in the film is straight out of French (or Broadway) farce, as Gust is repeatedly asked to absent himself from Charlie’s office as the congressman deals with other crises.

While one could have expected most filmmakers, even these, to hammer home the story’s dark contemporary irony, it’s handled lightly, with a beautiful line of dialogue about how the ball you’ve set in motion can keep bouncing even after you’ve lost interest in it. There’s no epilogue, only a framing device that seems to sincerely honor Charlie’s efforts to a surprising degree.

But it’s a film that adores character, something everyone here has in spades in one way or another. The book’s Joanne Herring comes off as hugely charming and sexually manipulative, whereas Roberts effectively plays her as almost single-mindedly cunning and Machiavellian. Amy Adams, a star since last weekend in the wake of “Enchanted,” is perkily energetic as Charlie’s adoring assistant; Ned Beatty has the old pro politician act down pat as a key recruit to Charlie’s cause; and Ken Stott gets off some wonderful lines and reactions as a crucial Israeli arms connection.

Craft contributions, notably Stephen Goldblatt’s lustrous lensing, Victor Kempster’s versatile production design and Albert Wolsky’s evocative period costuming, are first-rate.