Jon Hamm gets his best big screen leading man role, and delivers, in “Beirut,” a smart, taut tale of Middle East intrigues from the screenwriter of “Michael Clayton” and the better “Bourne” movies.

It’s a period piece built around a diplomatic shaker and mover who loses it all, and who doesn’t seek redemption or deliverance, just a return to a life of relevance.

Mason Skiles is the guy on America’s Lebanese embassy staff who makes the deals, a nuts and bolts arbitrator with an eye for the big picture and an ear for the apt metaphor.

Lebanon, he says, is like a boarding house filled with Arabs, Christians, French, Syrians, tribes with “2000 years of revenge, blood feuds and vendettas.” The Palestinians pounded on the door, begging to be let in after Israel declared its independence and they were forced out.  All these boarders in their Lebanese home — Beirut was “The Paris of the Middle East” until the early 1970s — have reached a level of tolerance. But they’re shocked when their new tenants “just want to burn down the Israeli house next door.”‘

He tells this story at a 1972 party, with he and his wife entertaining the elite of Beirut and U.S. Congressmen. It’s a Beirut bubble of Cadillacs, congressmen and cocktails. And for Skiles, that bubble bursts in a hail of bullets and a burst of post-Munich Olympics terrorism.

Ten years later, he hits the bottle too much, the flask even more and sometimes can’t even make it back to the budget motel without dozing off at the wheel of his Ford Pinto. He’s arbitrating small company labor disputes, a broken widower with a head full of skills he’s wasting on union mugs and corporate thugs.

But he’s summoned. He’ll “guest lecture” at the American University of Beirut. “The Company” needs him to negotiate the release of an old friend and colleague. Only Mason will do.

This isn’t explained until he’s on the ground, picked up by an Agency attache (Rosamund Pike). The guy in charge (the formidable character actor Dean Norris) sugar coats the request — “Putting a skirt in front of a jet-lagged (and hungover) man your age” tends to get results, he chuckles.

Shea Whigham is the military man on the ground, trying to limit Skiles’ role to just the conversations the kidnappers have demanded he lead. They’re all worried that the Israelis are looking for an excuse to invade Lebanon and end years of artillery and rocket attacks by the PLO.

Everybody’s motives are suspect.

It takes just one grim, blunt and blood-spattered meeting in a gutted, war-torn Beirut for Skiles to show his “particular skills.” Before self-help books put this on the cover, he’s a master of “getting to ‘yes.'”

“We’re just here to see if the market’s open,” he offers. Barking at him, saying “Out of the question” doesn’t rattle him. “Hypothetically, just for fun” he counters.

The CIA and military folk are taken aback. The Palestinians, Israelis and Embassy staff are knocked on their heels.

“You’re delusional,” he’s told.

“We’re in PLAY,” he barks back.

Who knew the mesmerizing ad-man of “Mad Men” would make a stellar peace broker?

Guilt, remorse, revenge, double-crosses and cover-ups play into Tony Gilroy’s tight script. And tradecraft, in spy parlance. Director Brad Anderson (“The Machinist,” “Transsiberian’) handles most of this with tension building mastery, though I will mention one quibble.

Characters scoot back and forth through factional sections of a city riven by artillery fire and snipers. And when they meet in the ruins of the “Paris of the Middle East,” inevitably, they’re standing in front of Peugeot or Renault headlights — a parade of sitting ducks scenes.

Hamm gives us everything we saw over the years-long run of “Mad Men” in an intricate, concise 110 minute movie — swagger, romance, hope and secrets, professional mastery and gutted personal oblivion.

Pike is her usual terrific, Whigham (“Boardwalk Empire”) perfectly non-plussed and Norris, Larry Pine (playing the ambassador), Alon Aboutboul (as a cagey Israeli) and Idir Chender (terrorist) are all first rate. 

There are no Bourne super-heroics, “surgical strikes” are a lie we haven’t been sold yet (it’s 1982 for much of the film) and no easy answers, just a grubby, clawing scramble back to status quo ante. Gilroy is no Le Carre and Anderson is no Scorsese, but this is a solid, thoroughly entertaining thriller.

Pity Bleecker Street has it. Chances are, nobody will see it. That studio couldn’t market a Marvel movie or merlot to a wino.

MPAA Rating: R for language, some violence and a brief nude image

Cast: Jon Hamm, Rosamund Pike, Shea Whigham, Mark Pellegrino, Dean Norris, Idir Chender

Credits:Directed by Brad Anderson, script by Tony Gilroy. A Bleecker St. release.

Running time: 1:49