Dress rehearsal of “Black Watch” at Shakespeare Theatre. The show is made up of the ensemble cast of the National Theatre of Scotland. (Astrid Riecken/For The Washington Post)

After Fair Isle sweaters, single malt whisky and Ewan McGregor, “Black Watch” may be Scotland’s most important export. The captivating play about a storied Scottish regiment’s deployment to Iraq is back on the road in this country again: it is on its second visit to Washington in 20 months, offering audiences another chance to experience this deeply moving, audaciously inventive account of ordinary soldiers convulsed by a war whose scope and politics they can barely comprehend.

Perhaps it was inevitable that the best portrait of the torturous extremes of life in a military camp — suffocating ennui relieved only by the scream and wallop of incoming mortar fire — would come from a backstage nook in the theater of war. Though Black Watch soldiers, with trademark red vulture feathers in their tams, fought ferociously for hundreds of years, they are portrayed in the National Theatre of Scotland production at Sidney Harman Hall as bit players in Operation Iraqi Freedom. In the American-led incursion, the Scottish troops find they’re far likelier to have to absorb an attack while confined to a base than to launch one themselves.

This strange, enforced immobility gives dramatist Gregory Burke and director John Tiffany the inspiration to explore the terms on which the members of a Black Watch unit confront Iraq, and the anger and anguish they carry with them back to Scotland. Based on interviews with Scottish servicemen, the play is an astonishingly evocative canvas for the bombings and boredom the soldiers encounter there, but whose effects they are barely able to articulate.

Despite the many wondrous elements of “Black Watch,” it must be noted that articulation is an issue in Shakespeare Theatre Company’s Harman Hall, where the piece is performed with the audience seated on opposing sides of the stage. Situated only a few rows back from the playing space, I could barely make out more than half of what the actors said. The combination of the authentically gnarly Scottish accents and the unyielding acoustics of the hall — is there a sound-sucking Phantom of the Harman? — creates far bigger audibility issues than there should be.

This was my third go-round with “Black Watch,” which was developed at Edinburgh Fringe back in 2006 by Tiffany, Burke, Steven Hoggett on movement and Davey Anderson with music — and my second with it in the Harman. I don’t recall the voices of the 10-man cast being quite this hard to discern before. And yet, the 110 minutes you spend with these excellent actors is anything but lacking in comprehensibility. By other vital means — video, choreography, sound effects, costuming, songs —“Black Watch” conjures the experiences of these rough young men so powerfully that you cannot leave the theater without the impression of their psyches having been seared into yours.

You will hear and feel, with shattering intensity, the impact of every mortar round and improvised explosive device aimed at their base, perched somewhere in the vicinity of Fallujah, where they have orders to back up American forces. In one of the many remarkable sequences, courtesy of Colin Grenfell’s lighting and Gareth Fry’s sound design, the Black Watch soldiers watch — as if admiring a video game — as American bombs incinerate a target, projected across the way, on a giant screen.

“Black Watch” alternates between moments when the war seems pure abstraction to these men — recruited from Scottish towns and cities on the strength of regimental honor — to instances in which their involvement becomes both poignant and horrific. The haunting sequence Hoggett choreographs with each soldier reading a letter from home while performing his own set of intricate hand movements, reminds us that every warrior brings his or her unique history to the war zone. The cataclysm to which the play builds, a split-second display of blood and shrapnel followed by a depiction of its human toll suspended in midair, is as affecting as any battle scene you’re ever likely to witness.

Burke and Tiffany, the latter a Tony winner this year for his direction of the musical "Once," offer not a trace of patronizing hero worship. (If anything, “Black Watch” suggests the naïve young fighters were bamboozled by recruiters who sold them on, among other things, glory.) The men are running faucets of profanity, unable to form a sentence without stringing together at least four corrosive words. Still, by evening’s end, we feel for the damage that’s been inflicted on each of them, especially on the touchstone character Cammy, played with gruff authority by Ryan Fletcher. (The other standout in this version is Robert Jack, as both the platoon’s sergeant and the interviewer of the soldiers as they hang out in a Scottish pub.)

Cammy has performed his duties so commendably that his commanding officer (Stephen McCole) informs him at play’s end that he’s in line for a medal. But Cammy’s done. He looks at his time in Iraq and sees only carnage. “And for WHAT?” he asks. The words, like the smoke from the suicide bombing he’s just had to clean up, leave a bitter taste in the air.

Black Watch

by Gregory Burke

Directed by John Tiffany. Movement, Steven Hoggett; music, Davey Anderson; sets, Laura Hopkins; lighting, Colin Grenfell; sound, Gareth Fry; costumes, Jessica Brettle; video, Leo Warner and Mark Grimmer. With Adam McNamara, Andrew Fraser, Richard Rankin, Chris Starkie, Cameron Barnes, Gavin Jon Wright, Scott Fletcher. About 1 hour 50 minutes. Through Oct. 7 at Sidney Harman Hall, 610 F St. NW. Call 202-547-1122 or visit www.shakespearetheatre.org.

“Black Watch” at the Shakespeare Theatre is based on interviews conducted by Gregory Burke with former soldiers who served in Iraq. (Astrid Riecken/For The Washington Post)