In Sam Shepard’s ‘Ages of the Moon’, not a lot happens. Two men drink, sitting on a porch. Nobody else comes along. One of them leaves, briefly. Most of what they talk about is objectively meaningless: rambling musings on life, alcohol, women; shared memories of past misadventures. A fan hums above them erratically, till one of them shoots it. They have a fight. One of them is hurt. It seems bad. They watch the moon.

The play is softly melancholic, with a streak of bleakness and despair, and a countervailing seam of hope and humanity. It is a gentle entertainment, in which the meandering earlier scenes, which are dominated by a sometimes-awkward burlesque comedy, lead to the payoff of a closing sequence of simple, stark beauty and emotional clarity.

The action, such as it is, takes place across a long day’s drinking, as the two men await a pre-dawn eclipse of the moon. One of the men (Stephen Rea) has been thrown out by his wife for having an affair; in distress, he has summoned his best friend (Seán McGinley) to join him at a rural retreat. The men are old, old friends; their tone with each other is laconic, occasionally antagonistic, all the while disguising real affection.

Stephen Rea is an extravagant clown to Seán McGinley’s straight man. Rea hams it up something almighty, but he is playing for absurdity rather than for straight laughs, stretching his face and frame into comically exaggerated positions, and then holding them, or refining them, till they become almost uncomfortable to watch. McGinley sits back and lets Rea do the work, till the final scenes. Then, Rea’s character is suddenly deflated, unsure, and McGinley holds the stage with a monologue of loss and loneliness that is riveting.

Sam Shepard is by now well known to Abbey audiences: this is the fourth Shepard play in three years that Jimmy Fay has directed at the Peacock, and the second play that Shepard has written for the Abbey, after ‘Kicking a Dead Horse’ in 2007.

That relationship is something of a coup for the Abbey, internationally. Since the 1920s, the Abbey has been a standard bearer for Irish culture in the US, in particular; though it is no longer alone in that regard, with Druid and the Gate surpassing the Abbey in terms of raw impact in recent years, the Abbey remains a touchstone for Irish theatre and culture, and it is important that it maintain an international reputation.

Brian Cowen spoke to this theme in his ard-fheis address. “Ireland is a brand,” he said. “Our country, her landscape and her culture are known the world over. We must connect with that brand now and use it to give us the competitive advantage in a globalised world that is increasingly the same.” You could spend all day parsing that statement for its implications for the role of the arts; most simply, though, it acknowledges that the work that the Abbey, and other institutions, do, is important in driving some sense of who we are in the wider world.

The relationship with Shepard is clearly also a boon to the National Theatre’s standing amongst our own theatre community; the presence of Rea and McGinley on stage is a statement of ambition and status for the Abbey.

These are good, pragmatic reasons for the Abbey to cultivate Shepard. But what of the principles? Does Shepard add to the ‘national theatre’? Are his plays talking to us as a nation – or are they simply glamorous imports?

Fiach MacConghail, the Abbey’s director, has said that a key reason to stage Shepard here is because of the strong influence of Beckett in Shepard’s work: Irish audiences can ‘get’ Shepard, in a way that, perhaps, other audiences can’t. (I am extrapolating from previous comments by MacConghail.)

Certainly, Beckett’s ghost is a looming presence in ‘Ages of the Moon’, though Shepard seems gentler and more optimistic in his vision. But while it may be of use to Shepard to have an audience that is (supposedly) closer to Beckett’s roots, I’m not certain that the relationship works in reverse. Beckett became perhaps the most influential playwright of the second half of the 20th century. Being influenced by him is not novel.

There is another Irish connection in Shepard’s work: the theme of rupture with the land. His characters are familiar to us, even though their speech sounds like something from the movies: they are sundered from their (sometimes mythical) past, a time when they lived in synergy with a harsh environment. But do we need four productions to explore this?

When I spent a few years burrowed away in a college drama society in the mid 1990s, Sam Shepard was one of the dominant influences. His plays were sexy, violent, ambivalent, sad, and required American accents; they had everything a student group could want.

Fifteen or so years on, there remains much that is attractive about Shepard’s work, and much that is engaging and provocative. He is a consummate playwright. But there are other companies putting on the work of leading international playwrights (Rough Magic this week brings us an Irish premiere by a leading Canadian writer, Michel Tremblay, ‘Solemn Mass for a Full Moon in Summer’, at the Project Arts Centre). For all their proficiency, the Abbey brings little more to Shepard’s work than did those student productions. There are a host of Irish writers under commission by the Abbey: the Peacock is their stage. Bring them on.

Written for my Saturday theatre column in the Irish Independent. ‘Ages of the Moon’s is at the Peacock Theatre in Dublin.