THE ARTS:Alfredo Jaar's artistic interventions have taken him from his native Chile to Bosnia, Rwanda and Sweden - but his concern now is with what's happening to the Leitrim landscape, he tells Belinda McKeon

In 1981, Alfredo Jaar was a young artist preparing to leave his native Chile for the freer cultural climate of New York. His Chile was a country in the grip of a military dictatorship which seemed to have wrung art and artistic activity to death; a Chile of tension and torture from which Jaar, then aged 25 and trained as an architect and film-maker, was understandably keen to escape.

Yet it was also, remarkably, a Chile in which Jaar had managed, over the course of three years, to create a series of starkly subversive artworks which stepped right up to the barbed-wire boundaries of Pinochet's regime, to the boundaries not just of what was permissible but of what was possible - and which traversed those boundaries with a determined leap.

Jaar's first public intervention, a series of performances, events and installations called Studies on Happiness, created a space for personal expression within an atmosphere of frightened silence.

Through street interviews, photo- portraiture, video recordings and public debates, he offered, to a people living within that authoritarian fist, the possibility of speech, the opportunity to question. In his Chile, even this much - to stop a person in the street and to ask them whether they were happy - was deeply dangerous. To question happiness, after all, was to question what was happening. To talk about feelings was to talk about facts.

Indeed, even in silence, Jaar found, there could be a statement. The intervention he made in 1981, following the Studies on Happiness project, was inspired by a newspaper photograph of Belfast women banging bin lids on the street to mark the death of another hunger striker in the Maze prison. Jaar took the noise of this image, its loud and unrestrained recognition of death, its naked assertion of injustice, and made of it a quiet moment of acknowledgment. He placed six bin lids, painted white, around the Chilean landscape, photographed them, then moved them on.

"It was a simple gesture," he says, "very mysterious, and if the police saw me, they couldn't do anything to me, they would just think this guy's insane. But then when I showed it in a museum, next to the clipping from the newspaper, it became a sign of death."

To mark death in a country where, at that time, people were dying in their thousands but without those deaths being admitted - the fate of the Chilean "disappeared" - was to make, within the uncanny silence, an unforgettable sound.

Over the last 30 years, Jaar has taken masterful possession of the public intervention, with its particular way of saying the unsayable, of sounding the unsoundable. For his interventions into culturally and politically contested spaces and situations, he has become one of the most respected artists of his time.

BASED IN NEW YORK, where he moved in 1982, he is most famous for his six-year project in Rwanda, which grappled with the genocide and what he calls the "criminal indifference" of the world community. This gave rise to 21 distinct projects, all concerned with notions of responsibility and representation. The Eyes of Gutele Emerita presented a million slides on a light table, all showing the same eyes - those of a woman who witnessed the butchering of her family - and all confronting the viewer with the plain, appalling fact of what happened in less than 100 days in 1994.

Often, Jaar's interventions - there have been some 50 of them since 1979 - have created some form of recognition for previously unseen victims, from Bosnian war survivors to North Korean famine victims, from Brazilian miners to Mexican immigrants. In a 1999 intervention, he rigged an ornate building in Montreal to flash red whenever activated by buttons installed at the entrance to three homeless shelters in the city. Embarrassed by the constant reddening of the city's night sky, and by what it said about the size of Montreal's homeless population, the mayor shut the project down.

Jaar also met with resistance when he offered to build a museum for Skoghall, a Swedish town virtually owned by the paper mill which formed its economic fulcrum. The townspeople insisted they didn't need any such thing. Yet when Jaar built them a museum entirely out of paper from the mill, and burned it down after 24 hours, they changed their tune - and now he has been invited, to his delight, to design a permanent Konsthall for Skoghall.

Though common themes and concerns may unite his public projects, Jaar insists that each intervention is grounded in the particularities of the place in which it is made. "They are responses to the essences of these places," he says, sitting at the vast, cityscape-sweeping windows of his Chelsea studio.

His ease as a teacher and a lecturer - he devotes a third of his time to such work, in international arts centres and universities, with the other two-thirds going to museum work and interventions - is evident in the eloquence with which he speaks, in a voice still strongly accented, about art and intent.

"I never studied art," he explains. "I'm an architect. And in architecture, when you design a building or a construction of any kind, you first analyse the place. That sense of place is fundamental in architecture. And that place where you are going to create that construction of some kind has an essence, that space. So the architect has to discover what is the essence. And then design according to the needs and the essence of the place."

A PLACE'S ESSENCE, he argues, is not just physical, not just about measurements and logistics and planning regulations. "Any place is a political place, it's a cultural space, it's a landscape," he says. "It is many, many things. So the architect analyses that, and proposes something that fits so well to that place, that is unique to that place, that responds to the history of that place, to the landscape, to the beauty of the place. And then, when you discover that essence, you can make a proposal."

He pauses, looks almost pained. "And that's what shocked me in Leitrim."

Leitrim? Yes, Leitrim. Tijuana, Catia, Fukuroi, Mälmo, Kwangju, and now Leitrim. Leitrim and Roscommon, to be more precise; for these are the two places which have been on Jaar's mind over the past year, as he has led a residency with five artists from the area.

Through arts officers Caoimhín Corrigan and Philip Delamere, the five artists - Carol Anne Connolly, Gareth Kennedy, Alice Lyons, Christine Mackey and Anna MacLeod - asked Jaar to work with them for a year. Enticed by what he describes as a "marvellous" letter of invitation and the chance to work in Ireland (which he had never previously visited), Jaar accepted. "I thought, wow, I'm famous in Leitrim," he says (and, however it might look in print, it doesn't sound remotely condescending, but genuinely surprised).

Jaar has met the five artists on a number of one-week visits over the course of the year, and this weekend he will speak at Trade, an annual event for artists in the Leitrim/Roscommon region, at which he will talk about some of his own recent public interventions and discuss the work he has done with the five Irish-based artists. The focus has been on guiding these artists in the creation of their own public interventions, and, says Jaar, a common concern quickly became apparent as the artists discussed potential sites of intervention.

All five artists will focus on the badly planned and barely designed property development which has run riot over the Leitrim/Roscommon countryside in the last five years.

"The new constructions you see in Leitrim are just appalling," says Jaar. "They do not correspond to that extraordinary landscape."

They fail abysmally to connect with the essence of the place, he says, "yet people still buy these places. Because they are looking at them only as an investment. It's as if architecture and development has become like money."

Jaar's tone is genuinely baffled at this point. What has happened, so quickly, in Ireland, is "unbelievable", he says. He has seen it elsewhere, but it is vastly more "visible" in "such a beautiful country, so small".

As an architect, how might he characterise the kinds of developments that are springing up like ragwort in villages across these counties?

"Ooh la la," he says, wincing. "What ugly but diplomatic word can I use?" He sighs. "Let's say it in another way. The developers are not enlightened. They think that the only way to make money is by building the cheapest and quickest and . . . I just think these developers are making a huge mistake. I think that good architecture is also valuable, and also pays. And it lasts."

ON THE QUALITY of new Irish housing developments, Jaar uses other words, not especially harsh words, but words he asks me not to quote all the same. In the speech he'll deliver at Trade, he warns about the dangers of landscape "deteriorating into parody" - strong words. He's excited about the "aesthetic intelligence" of the five local artists who are making work around the subject of property development, but he seems wary of saying too much on the subject himself, wary of overstepping some mark of propriety.

Jaar has also been asked by the Dublin Docklands Development Authority to make a temporary intervention next summer, but he feels "the same kind of disgust" at the rapid and underplanned development in that area, so he is still deciding "whether an intervention in that context is worth it". He likes his interventions to have some chance of making a difference, he says.

Dictatorship, genocide, famine, xenophobia, injustice - Jaar's work has squared up to it all. But he'd never seen an Irish property development before. It obviously takes some beating.

The Trade seminar takes place at King House, Boyle, Co Roscommon, today and tomorrow. Further details: www.roscommonarts.com