AN EXHILARATING BLAST OF BRITISH RANCOR, In the Loop is smart, funny, and almost serious. Cautiously, director and co-writer Armando Iannucci hasn't included any details that certify that the comedy is about what it's clearly about: how the Brits and the Yanks talked each other, and themselves, into invading Iraq. The film doesn't actually examine the background of that debacle. Instead, it just uses an Iraq-like situation to satirize the working of high-stakes bureaucracy on both sides of the Atlantic. In the Loop is a political burlesque in which ideology doesn't especially matter.

Although the film is set mostly in the national-government precincts of London and Washington, there are no counterparts to George W. Bush or Tony Blair. Everything operates down a step or two, at the level of senior advisers and junior cabinet members — and the bright-eyed apprentices who aspire to someday have those moderately important jobs. One of the British characters sneers that the White House is full of kids; "It's like Bugsy Malone, but with real guns." Yes, and In the Loop is The Office, but with a real war.

The conflict begins when Simon Foster (Tom Hollander), the cabinet minister for international development, is queried by a reporter about the war that's clearly being plotted. Foster responds, meekly and inanely, that war is "unforeseeable." This comment riles the movie's charismatically ornery archfiend, Malcolm Tucker (Peter Capaldi), a Scottish hothead based in part on former Prime Minister Tony Blair's spokesman and enforcer, Alastair Campbell. Foster just makes things worse in a subsequent interview, saying that the British government must "climb the mountain of conflict."

In Washington, Foster's banality is taken as a slogan by State Dept. warmonger Linton Barwick (David Rasche). But anti-war State Dept assistant secretary Karen Clarke (Mimi Kennedy) and her ex-beau, top Pentagon official Lt. Gen. George Miller (James Gandolfini) think Foster has revealed himself as a dove. So Clarke invites Foster and inexperienced aide Toby Wright (Chris Addison) to D.C. There, they encounter Clarke's assistant (Anna Chlumsky), who had "a little fling" with Toby back when they were both at the same Oxbridge grad school.

Like a Sex Pistols song or a Martis Amis novel, In the Loop depends on the contrast between full-bore misanthropy and Britain's reputed gentility and reserve. Tucker lobs profanities with every breath, and acts as if he'd be happy if everyone he meets would simply wither and die. (We don't see him with his boss, of course.) The other Brits react with resignation — notably, Foster's repeated realization that he's been invited to a conference just to serve as "room meat" — or with failed attempts to act as tough as their tormenter: Foster's communications director (Gina McKee) protests that she can take verbal abuse because "my husband works for Tower Hamlets," the borough that's London's version of the 'hood.

In the Loop is an offshoot of BBC series The Thick of It, which is set in Whitehall and also features Capaldi. Not surprisingly, the movie gets a bit lost once it lands in D.C.: Foster and Toby arrive at National, not Dulles, and two mad dashes to the State Dept. involve characters who race in the wrong direction. The many geographical gaffes will bother only people who know their way around the city, but such location bloopers reflect a larger problem. Iannucci has said he researched official Washington's diverse styles of swearing, but he didn't dig far into U.S. government or diction. He even has Barwick announce that "it's early days" — a Britishism no American would use.

Droll as it is, the movie is less convincing on the run-up to the Iraq War than on British irascibility. None of the American characters are as compelling as the peeved Foster constituent (a well-disguised Steve Coogan) who demands that his M.P. deal with a collapsing garden wall. The Iraq stuff is either genuine but with the names changed — unreliable anti-Hussein informant "Curveball" is here renamed "Iceman" — or too blunt to cut deeply.

In its final scenes, this foul-mouthed sitcom begins to exhaust its powers of invention. Tucker must keeping topping himself, and so turns to physical assaults (just against inanimate objects). Iannucci seems a little desperate when he introduces a new character, Tucker aide Jamie MacDonald (Paul Higgins), who's simply a clone of his boss. The final, post-credits capper is another Tucker tirade, but the crucial scene is between two of the other British characters: "I'll leave you to your thoughts," says one; "I don't have any thoughts," replies the other.

That's In the Loop's essential insight: that the Brits went along with the war because they couldn't think of anything better. Left off-screen are the people — let's give them the aliases Cheney, Wolfowitz, Feith, Perle, and Libbey — who had lots of thoughts, all them wrong. It would be hard to make them amusing, but an Iraq-war satire that excludes them is out of the loop.

IN THE LOOP — 2009, 106 min; at Landmark E Street and Bethesda Row.

PITY THE EARNEST GEN X OR Y HETERO GUY. He's so accepting of homosexuality that he worries he's undercutting the zeitgeist by being straight. At the very least, he broods — in the manner of writer-director Kevin Smith — that women have been granted a free pass to bisexuality that he wasn't issued. He worries that every male friendship is a fraud, since the buddies's comradely hug doesn't lead to copulation. When pressed, Gen X/Y-H guy feels he has no choice but to set up a video camera and record himself engaging in "beyond gay" sex with a longtime Gen X/Y-H pal.

At least that's the premise of Humpday, a smalltime comedy so tedious it's hardly worth mentioning — except that its sexual panic has already been reflected in a raft of bad-boy comedies that fret about the implications of "bromance" and chortle with horror at full-frontal male nudity. If other guys's penises are the most frightening things in these kids's lives, maybe it's time to bring back the draft.

Apparently inspired by Seattle alt-weekly The Stranger's homemade-porn festival — and conceived by a woman, writer-director Lynn Shelton — Humpday is about two guys who get stoned and commit, in front of witnesses, to making a same-sex "boning" video for Hump fest. Ben (Mark Duplass) has settled into middle-class, home-owning life, complete with the complication of a wife, Anna (Alycia Delmore), who's ready for a baby. Then his boho pal Andrew (Blair Witch Project survivor Joshua Leonard) crashes into town, fresh from Chiapas or wherever. At a party Anna declines to attend, the guys decide to make the sex tape. Then they spend the rest of the movie discussing their half-baked idea, trying to sell it to Anna — and to themselves.

Since Humpday is all talk, it would help if the conversations were clever. Alas, the script is entirely too realistic: Ben and Andrew don't really have anything to say. (Maybe that's why their gesture will matter only if it's preserved on video; to post-literates, actions don't need to be understood, just viewed.) Even the few corroborating details the guys provide ring false: Ben professes that, when he was 18, he had a crush on a male video-store clerk who recommended a Frank Lloyd Wright DVD. But unless the potbellied dude is a lot younger than he looks, no store was renting DVDs when he was 18. That's the kind of sloppiness that characterizes the movie. Humpday is about two phony characters with a fake problem, so it where else can it end but with a sham resolution?

HUMPDAY — 2009, 93 min; at Landmark E Street.