Three hours of dense writing and 21 characters engaged in incessant onstage negotiations ... doesn't sound like potentially engrossing theater, does it?

Oh, but it is. J.T. Rogers' Oslo, after a run at the Lincoln Center's smaller Newhouse Theater, reopened Thursday at the larger Vivian Beaumont space -- and is likely to become the theatrical award magnet of 2017 by defying all manner of received wisdom in its dramatization of the 1993 Oslo Accords.

This painstaking, behind-closed-doors account of how Israel and the Palestinian Liberation Organization came to recognize and talk to one another is told with a level of intricacy -- and with a handsome production package -- that could be launched only in the realm of nonprofit theater. Commissioned by Lincoln Center Theater, Oslo was developed at the PlayPENN development workshop in Philadelphia (which has midwifed 100 plays since 2005). Best known for the play Madagascar, Rogers has had several residencies there.

The results are demanding. At the Sunday preview I attended, people I know exited at intermission for the simple reason that there's so much shouting. But what can you expect when Israelis and the Palestine Liberation Organization, acting on thousands of years of hostilities, gradually inch toward each other with the genteel nudging of mild-mannered Norwegian diplomats? Even more unlikely, the diplomats constitute the dramatic core, as they're too quiet to be conventionally heroic but are risking their careers on purely idealistic grounds. They have observed Arab and Israeli boys of the same age trading murderous glances on the Gaza Strip, and they are determined to succeed in a situation the rest of the world considers hopeless.

Much of the play is about strategies that are well beyond the realm of diplomatic convention. A seasoned dramaturge wouldn't have been wrong to recommended that the character count be halved and that numerous details about diplomatic protocol be cut. But the inclusion of such things is what gives the play so much of its cumulative power, as the diplomats build a fragile house of cards, sometimes buttressed by half-truths, and with differences resolved by means as simple as liberal amounts of alcohol.

As cerebral as the package sounds, the emotional impact is such that you're not surprised when hardened Arabs are reduced to tears over finally being recognized. And you might be blubbering along with them. Another masterstroke: Just when the plot has reached an apparent impasse, comic German tourists stumble in with longstanding reservations to rent the villa in which the negotiations are unfolding.

The single-set production designed by Michael Yeargan establishes an expansive, old-world atmosphere. Video projections and lighting changes accompany flashbacks, flash-forwards, and moments of narration essential to setting up the chess pieces in this international game of changing history. One antecedent for this play is Lee Blessing's 1988 Walk in the Woods, about U.S./Soviet arms negotiations. But that was chamber music compared to the symphonic grandeur of Oslo.

Oddly, the play has no dominant role. The hallmark here is the ensemble. Of course, the deepest admiration goes to the Norwegians, played by Jennifer Ehle and Jefferson Mays, because they so easily capture their singular world, in which romance is enhanced by diplomatic breakthroughs. Yet they come within an inch of betraying each other for the sake of defusing an impending checkmate.

Act 2 is invaded by Michael Aronov as Uri Savir, a flamboyant Israeli who brings a curious, swaggering sex appeal to the negotiating table. On the Arab side, Anthony Azizi consistently reveals a considered mind at work amid volatile proceedings -- and makes his character into one of the play's most charismatic. I'm not sure I'd want to see Oslo with anything but New York-caliber actors -- or with anything other than Bartlett Sher's direction, which you almost don't notice, so organically does it serve a play that, in my humble opinion, has Tony written all over it.

Oslo. Through June 18 at the Vivian Beaumont Theater at Lincoln Center, 150 W. 65th St., New York. Tickets: $77-$147. Information: 800-432-7250 or lct.org.