What makes Triumph of the Will worth viewing:
Considering the evils of the Nazi regime, why should we wish to see one of its propaganda movies? Leni Riefenstahl's talents are certainly on display here, but talent by itself does not justify a work's existence, especially an evil one. While freedom of expression as a universal right justifies the decision not to punish her for making the movie, it also does not absolve her of guilt for its intended effect: the glorification and promotion of an evil and genocidal ideology.
The real reason this film ought to remain available, and why everyone ought to see it at least once, is for educational purposes. To be sure, the lessons to be learned from this are not the original beliefs it was intended to instill in its viewers: we know, now, where these beliefs ultimately lead. Neither should we merely be stopping to admire Leni Riefenstahl's talents, even her talent for deception. (Many of the tricks she used to make Hitler and his Nazis seem larger-than-life are still used in Hollywood to this day.) None of the techniques used in the movie were new, but - especially the expensive ones like aerial shots or mass scenes or elaborate night shots with artificial light - they were used in such an extent as to be overwhelming. A minute of aerial shot is nothing impressive, a few hundred Nazis is not impressive. The sheer volume employed shows the regime either had millions of genuine enthusiast supporters or enough resources to make people pretend to be enthusiasts supporters. In short, the entire point was to overwhelm and to make opposition not only seem undesirable but pointless and impossible against the sheer might of the Nazi Party. This of course was untrue at the time the movie was made, as the party was rather shaky, not yet having solidified its control over the army (see below) and going through an internal purge in which several erstwhile top Nazis were murdered and declared Un-person (hence why the 1933 Nuremberg Rally and the Leni Riefenstahl movie based on it were quickly shushed up and put in the least visible crannies of the archives). The movie in short is not there to show any true thing, but to show the Nazi party as unified, powerful and inevitable when it was none of these things.
What this movie helps us understand, better than many other works of propaganda from Nazi Germany, is what the whole appeal of Nazism was: why its followers were so devoted to it, how it persuaded them to do such terrible deeds, and why so many of them followed it to the bitter end. Triumph of the Will gives us a very good insight into the "ism" in Nazism: here, on the screen, are the Nazis as they saw themselves, promoting what they actually believed and really wanted everyone else to believe. The conspicuous absence of both the Jews and any direct mention of them serves to underscore that this movie is not about Nazism's stick but about its carrot: the scapegoating of the Jews for Germany's problems and the Nazis' plans to purge the earth of them, along with (eventually) every other non-Aryan race, are held out for some other movie some other time.
The Million Mook Marches are particularly instructive. The vast majority of them are, appearances to the contrary, not military. In fact, upon screening this film, many German military officers (as aristocrats still skeptical of the "upstart" Hitler who had only risen to the rank of private during the war) complained about Riefenstahl's apparent neglect for them, as they were never on screen for five whole minutes of running time; she would later make the short film Day of Triumph to rectify this alleged oversight. To the untrained observer, however, it might seem that one was seeing nothing but military formations on the screen. Everyone, from the post office employees to the vehicle registry officials, is wearing a uniform and marching in unison. The movie thus was also intended to show the - not too small number - of skeptical military members that even if the entire old military brass were to oppose the regime, it could put enough people in uniform - and if need be under arms - to crush any possible military uprising. Whether this, the swearing in of new soldiers containing an oath directly to Hitler or sheer dumb luck caused military figures who opposed Hitler to hesitate cannot be ascertained, but while there was a plan to assassinate and/or topple Hitler during the Sudeten crisis of 1938, it took the anti-Hitler voices in the military until 1944 (when the war was basically lost already) to finally act in a major way with the attempted "Valkyrie" coup.
This, arguably, is what lies at the heart of the film, and its horrifically successful appeal to the German people to become Hitler's willing exterminators. In Nazi Germany, the film is telling us, every loyal citizen gets to have a spiffy uniform and be part of a glorified organization which in turn is a valued part of an even more glorious national purpose. The Aryan ideal is presented to us not so much in the speeches as in numerous scenes in which the camera lingers over handsome blond-haired children and youths with straight teeth and clear skin. The loyal Nazi is offered, in not so many words, the opportunity to have this physical perfection: to be beautiful both on the inside and the outside.
Above all, however, the sheer number of German agencies and industries on display reveals the other source of Nazism's appeal: the Nazi Party was everywhere, it was everything, and it was everybody. If you were a German citizen, the Nazis were not just your government or military, but also your post office, your department of motor vehicles, your corporate headquarters, your trade union, your church, your school, your Boy Scouts (particularly all those handsome Hitler Youths we're shown camping out and engaging in some camp sports ahead of one of Hitler's big events), and your neighbors. To oppose the Nazis, to disagree with their ideology, was to oppose every one of these people and institutions all around you; it would seem you were opposing humanity itself, or at least all the humanity that mattered.
This, then, is why we should keep this movie in our archives and, when each upcoming generation reaches an appropriate age, show it to them: so that we can make them understand the awful power of state propaganda and teach them how to identify it so they can resist it. Swastikas and other Nazi symbols will probably never regain their former luster. Some of the Nazis' more peculiar rituals such as the touching of their country's flag to its soil (and to the Party's first flag as a way of transferring a kind of mystical quality it was thought to possess to them) will never translate well enough to be carried over into any other country's customs and traditions.
Nevertheless, other ruthless totalitarians bearing other symbols and engaging in other forms of pageantry will surely arise, seeking the allegiance of the ignorant and ill-informed through more of this kind of propaganda. Reminding these easily-influenced souls of what happened the last time a people not so different from themselves fell for such a ploy and showing them one of the most effective tools the previous totalitarians used to manipulate them should go a long way toward remedying these contemporary targets for indoctrination of their gullibility.