The true art of the deal — the kind that actually matters — is comprehensively outlined in J.T. Rogers’s intelligent and personality-rich diplomacy play “Oslo.” Reconstructing step by step the secret talks that resulted in a historic agreement in 1993 between Israel and the Palestine Liberation Organization, the playwright manages the deft feat of making complex aspects of realpolitik the stuff of incisive entertainment.

Round House Theatre, taking up residence for a spell at the Lansburgh Theatre on Seventh Street NW while its Bethesda venue is being renovated, provides this Tony-winning play an excellent regional premiere, under Ryan Rilette’s direction. For the city’s constellation of embassies alone, “Oslo” should be a natural draw. But any theatergoers with an interest in the world beyond their own backyards — or an admiration for the painstaking challenge of getting enemies to a negotiating table — will find much in “Oslo” to savor.

The cast assembled for the task of conjuring the Oslo talks, which planted the seeds for Palestinian self-government and a fleeting hope for Middle East peace, proves satisfyingly up to the demands of Rogers’s dauntingly lengthy script. Clocking in at nearly three hours, “Oslo” might benefit from a delicately handled trim. Still, such accomplished actors as Cody Nickell and Erin Weaver, playing the tireless Norwegian couple who took it upon themselves to attempt what American negotiators failed to do, succeed in conveying the magnitude of commitment required to close a monumental deal.

Many audience members will carry into the Lansburgh memories of the historic Rose Garden moment of 26 years ago, when PLO Chairman Yasser Arafat and Israeli Prime Minister Yitzhak Rabin shook hands — and shook the world in the process. They also bear the knowledge of the dispiriting aftermath: that the Oslo accords were not to be the prologue to lasting peace. The play, in that respect, is a bittersweet testament to in­trac­table acrimony.

What better location these days for such a stage narrative than Washington.

On Misha Kachman’s eye-pleasing set, embellished by Jared Mezzocchi’s projections — movable walls of artificial wood and stone on which flash bucolic Scandinavian landscapes — Rilette moves the personages from recent history through “Oslo’s” myriad scenes. From Norway to Israel to Tunisia the play bounces, over phone lines and meetings over drinks, tahini and waffles. An early monologue by Nickell’s Terje Rod-Larsen, the idiosyncratic foreign-policy thinker and catalyst for the talks, lays out his diplomatic theory: “gradualism,” a belief that adversaries can root negotiations in personal connection rather than in what their organizations represent.

To keep any trace of dryness at bay, “Oslo” imposes heightened pressure on its actors to establish their characters as singular. The most successful players in this epic canvas happen to be Weaver, as Terje’s wife and Norwegian foreign ministry staffer Mona Juul, and Maboud Ebrahimzadeh, portraying Ahmed Qurei, the chief PLO negotiator. They stand out because their portrayals embody their tenuous positions most effectively: Weaver uses the steel in Mona’s makeup as a compelling counterbalance to her altruism and worry about her job, and Ebrahimzadeh locates in Ahmed the sensitive human being threatening to emerge amid the testosterone-fueled posturing and the platitudes.

Nickell’s Terje captures the busybody proclivities of a preternatural meddler, but it would not have hurt if Rilette had encouraged him to more clearly reveal the text’s suggestions of what a pain in the neck Terje could be. A scene late in the proceedings, in which the negotiators on both sides join in good-natured mocking of Terje, would be funnier if this trait had a bit more foundation. As for Juri Henley-Cohn’s Uri Savir, who emerges as chief Israeli enforcer of the views of his superiors back in Jerusalem, the suaveness of the character is apparent. But he could make more of Uri’s swagger. His role in “Oslo” is to dial up the tension, after the initial negotiators (played by Sasha Olinick and Gregory Wooddell on the Israeli side; Ebramimzadeh and Ahmad Kamal for the Palestinians) become all too friendly.

Michael Sweeney Hammond proves a nuanced comic asset in his turns as a Norwegian security man and a U.S. Embassy staffer; Kimberly Gilbert, portraying a Norwegian housekeeper who cooks for the negotiators, evokes the refreshing amiability of a working-class woman plopped down in extraordinarily trying circumstances. And Conrad Feininger makes for an exceptional Shimon Peres, who, with a late-night phone call to Arafat, brought the talks to an emotional finale.

While these actors all help you see how the pieces of a puzzle with global consequences fell into place, you’re left with increasingly conflicting emotions. For even as you share in the glee of bureaucrats from a small Northern European nation pulling off a remarkable coup, you’re reminded of how transitory their success was. Is “Oslo” a depiction of triumph, or futility? Rogers’s achievement is that the answer has to be: yes.

Oslo, by J.T. Rogers. Directed by Ryan Rilette. Set, Misha Kachman; costumes, Ivania Stack; lighting, Jesse Belsky; sound and music, Matthew M. Nielson; projections, Jared Mezzocchi. With Todd Scofield, Alexander Strain and John Austin. About 2 hours and 55 minutes. $50-$77. Through May 19 at the Lansburgh Theatre, 450 Seventh St. NW. 240-644-1100.