Breathtaking is the best word we can think of for “They Shall Not Grow Old.” That is the Peter Jackson documentary in respect of the soldiers who took the fight to the Germans from the trenches of World War I. The film consists largely of footage taken at the front. It has been refurbished, colored, and overlaid with narratives spoken by those who appeared in arms.

These columns are hardly the first to grasp the significance of Mr. Jackson’s achievement. Millions have just finished marking the centenary of the Armistice that ended the carnage of World War I on the 11th hour of the 11th day of the 11th month of 1918. Millions, too, are trying to process the possibility that the globe could yet again be trembling on the edge of another world war.

Yet what floors us about “They Shall Not Grow Old” is the artistic achievement. The movie was years in the making, having been launched by Britain’s Imperial War Museums something like four years ago. Mr. Jackson who is both the director and producer, includes at the end a half hour bonus, consisting of an explanation of the techniques used to bring the century old footage to new glory.

The artists used the latest computer technology to clean up the often scratched and warped images. They had to figure out what was the real-time speed at which to run the footage, whose speed varied from hand-cranked cameras on which it was originally captured. They hired lip-readers to figure out what was being said by some of the doughboys filmed talking.

Plus, too, the film-makers had to edit, match, and splice the recorded memories that had been amassed by the War Museums and others over the years. Some described images for which there was no film, such as the hand-to-hand combat that took place once the British broke the German lines. Then, in an inspired stroke, Mr. Jackson drew on drawings from a magazine called “The War Illustrated.”

Mr. Jackson has included ample footage of one of the astounding features of trench warfare, the degree to which it was fought by the King of Battle, namely artillery. The power of the pieces used in World War I is astonishing. Mr. Jackson has uncovered footage of the German shells reaching their mark among the British with terrifying results. He uses slow motion to capture the power of German mines.

The greatest art in the film, though, are the panoramas of the Hellish battlefield. The result is tableau after tableau of scenes evoking John Singer Sargent’s “Gassed,” save for the fact that the motion picture cameramen better than the painters caught the full battlescape. The Imperial War Museums’ footage, too, is far more ghastly — dead men and horses — than that done by the World War I paintings.

One reason the artistic achievement is so magnificent is that it is unsullied by politics and ideology. This is neither an anti-war film nor a propaganda exercise (it includes affecting footage of the Germans). Such statement as there is in the film is in the title, “They Shall Not Grow Old,” a sort-of Dorian Gray-like reversal in the sense that Mr. Jackson has made the images of some of the century’s bravest men not only fresh again but also, finally, immortal. And if that’s not art, we don’t know what is.