Allen and Diane Keaton are brilliant, deadpanning a very Noo Yoik type convoluted love-affair into a cod-Tolstoyesque (or sometimes even cod-Dostoyevskyan) setting. There are some fabulous exchanges between Keaton's philosophical Sonja and Allen's wise-cracking Boris. And the supporting cast do fine as well, Keaton's first (herring merchant) husband, her unctuous piano-teacher - the first of her many lovers - and James Tolkan as Napoleon, are all noteworthy. Numerous other actors give brief but entertaining performances, such as the guy who portrays one of Napoleon's forgotten staff, Sidney Applebaum.
The first and only major military campaign depicted on film here is, as in War and Peace, the 1805 campaign, which culminatesd in Austerlitz. In this film, Allen doesn't - as mainstream American directors would undoubtedly do - signpost such references (and the film is littered with cultural cross defences), they're there for the knowing to spot and enjoy.
The second military phase is of course the 1812 invasion, but again history, military and civil, just serves as a vehicle for Allen's comedic take an everything from sex and art, to angst and philosophy. This is the segment in which Boris is not a soldier, but a would-be assassin. So it's not so much battles, as intrigue, Boris and Sonja inveigling their way into the Imperial HQ.
In a film like Bondarchuk's Waterloo, one might lament any license with history. Here, however, we are clearly dealing with a film in which historical accuracy was not paramount. Nevertheless, the uniforms and settings are, for the most part, pretty good - and certainly sumptuous and quite spectaular - but mostly it's just great fun to see a favourite era used for comedic mileage.