It seems odd to have to explain who Alain Resnais is, or his significance in the history of cinema. At the peak of his reputation, when "La Guerre est Finie" was made, he was viewed as one of the world's most innovative and important filmmakers. No one with even the remotest interest in film would have been unfamiliar with his name. Speaking personally, few have influenced me as deeply as he, in both technique and thematic interest.
Time moves on, however, and while Resnais will certainly have a place in film history, it will probably not be because of "La Guerre est Finie." It is clearly a product of its time, not just because Spain's subsequent history has blunted much of the film's thematic bite, but more because of its rather too self-conscious pensiveness. While the subject of a Resistance fighter moving across borders could work as an action film, "La Guerre est Finie" deliberately avoids much suspense in order to dramatize the dull stretches between high points.
This focus is certainly preferable to hyped-up action, but unfortunately Resnais and screenwriter Jorge Semprun do not so much reveal and evoke as replace one set of conventions with another. If you have seen any European, particularly French, art films from the 60s, you know what to expect: lots of philosophical talk, endless sequences of characters rolling around in bed, much political attitudinizing, and even more pointless walking around the streets of Paris. "La Guerre est Finie" is hardly alone in using these clichés, but that's the point. In what is supposed to be an in-depth examination of a character in crisis, fashion substitutes for observation and the results have more to do with filmmaking habit than any real grappling with the subject. (With one exception: the debates in the Communist cell to which the main character belong, thick with the pedantic rationalizations that give Marxist theory a bad name, feel like the gentle parody of a knowing insider.)
Which is not to suggest that "La Guerre est Finie" is either cheap or tawdry, merely banal in everything other than form. The camerawork and editing are so superbly rhythmed and timed you don't much care about the subject. (Given his talents, it's a pity Resnais has never made a musical.) Ironically, though perhaps inevitably, "Guerre" is most effective in the suspense scenes. It is nothing much better than respectably well-meaning as character drama; as formal exercise, on the other hand, it is peerless.