That we know de Gaulle was not assassinated makes Zinneman's achievement all the more remarkable. This is a film crafted with genius.
He's taken Frederick Forsyth's fine thriller and improved upon it in almost every particular. The plot is more logical, the pace tighter; the characters retain their intense and personal distance (essential for the plot), but are somehow far more human and calculating, and the suspense is palpable.
There have been many cat-and-mouse stories of the detective tracing the criminal, but none so effective. Just to appreciate how good the original is at the art of film-making, compare it to the dire American remake starring Bruce Willis and Richard Gere.
The directorial techniques used are stunningly effective: freeze frame highlights key moments. Silence is used to stunning effect, particularly at the climax which creeps upon the viewer without being signposted by creepy music - big improvement that other directors could do well to note.
The cool ruthlessness of the Jackal is beautifully drawn out by Edward Fox, using the meticulous planning process to tune his character's determination to suceed in the assassination.
By contrast, Michael Lonsdale's detective, burdened by the awesome responsibility of saving France, applies to the task with dogged and passionate determination. That he succeeds is not enough for his own satisfaction - he does not know his enemy, and never really knew who he was chasing.
This film has consistently stayed in my personal top 10 of all time since way back when. DotJ has been accused of being emotionally cold and lacking human warmth, but it strikes exactly the right balance between steely realism and hypothetical retelling of history - one reason why the remake is hokum by comparison!