Directed by Julio Medem

A few years ago, a two-hour, interview-based documentary on the Basque conflict would have little chance of making it to the cinema.

A new market for feature-length documentaries on the big screen has emerged. This could be remembered as a golden age for the genre, with 'Être et Avoir', 'Bus 174', 'Winged Migration', 'Spellbound', 'Capturing the Friedmans', 'The Fog of War' and 'Touching the Void' all enjoying commercial and critical success.

Julio Medem hails from the Basque country and made his name directing movies like 'Sex and Lucia' and 'The Lovers of the Arctic Circle'. 'The Basque Ball' is his personal project, painstakingly constructed from hundreds of hours of interviews with protagonists of the bloody Basque nationalist conflict.

The interviewees are a mixed bunch, from senior politicians including ex-Spanish Prime Minister Felipe González, to intellectuals, writers and, most movingly, relatives of those murdered or imprisoned.

It's hard not to draw parallels with the situation in Northern Ireland. The Spanish government's hardline strategy is blamed for prolonging the conflict, but few of the interviewees are enamoured with ETA, the paramilitary group who have shot and bombed their way to notoriety in the name of their homeland.

Few of the many faces are familiar, Felipe González and the Belfast Redemptorist Fr Alec Reid were the only people I recognised, with the exception of the archive footage of a 1955 Orson Welles documentary. For a viewer with no previous knowledge of Basque culture this film could be impenetrable.

Medem conjures some wondrous visual splendour, the camera rushing airborne through river-carved ravines and above blazing fields, but also edits his interviews ruthlessly, removing pauses and digressions with jump-cuts. The effect is staccato, making the viewer uneasy. One sentence is knotted together by six cuts, making it hard to tell if the person actually said it in the first place, leaving too much trust in Medem's hands.

The film is also too long at 115 minutes, and the dynamic pelota sequences and dramatic archive footage don't add enough to what is really a collection of interviews.

Having said that, these testaments are often moving and sometimes perceptive. "The choice is not between nationalism and non-nationalism, but between civilisation and barbarity" is the essence of many conflicts around the world. Another commentator pinpoints the toll that pointless struggle takes on its participants, "the useless effort leads to melancholy". As a lesson, that's hard to beat.

Luke McManus