Perhaps because it came out so soon after Pontecorvo's classic "La Battaglia di Algeri" (The Battle of Algiers), "The Lost Command" got, well, lost. That's too bad, because I saw this movie only once about 20 years ago, but still recall it vividly as a surprisingly well-done action film spiced with social commentary that doesn't overwhelm the whole.
Anthony Quinn is especially believable as a hard-bitten professional soldier who manages to rise to high command in spite of his peasant birth. Alain Delon is his pretty boy right-hand and George Segal has a particularly interesting turn as an Arab serving with Quinn and Delon in Indochina at the film's beginning who is radicalized upon returning to his native Algeria and takes up arms against his former comrades.
The highlight of the film is its retelling of the Battle of Algiers, with Quinn in the role of the real-life para colonel Jacques Massieu.
The battle scenes are well-done and realistic, especially the opening sequence, which is set in the final, desperate hours at Dien Bien Phu in 1954. Despite being well-made and underrated, this film is not often shown on television, so you'll probably have to rent it.