Perhaps even more than his ground breaking short work, The Great Dictator is Charlie Chaplin's most important and daring work. At the time when world leaders, never mind Hollywood studio bosses were reluctant to annoy Hitler, Chaplin had the guts not only to put his reputation and money on the line, but to make the end product largely free from pious moralising, instead going for the giant raspberry in the face of the despot.
The plot is a slightly contrived piece of farce. Chaplin plays a barber (unnamed, just like his tramp character), from the fictional country of Tomania. During military service during the First World War, he saves the life of Schultz, a German pilot, crashing a plane and giving himself amnesia for 20 years. He eventually returns to his barber shop, only to find that a dictator, Hynkel, who is also a dead ringer for the barber, has come to power, and his goons are sweeping through the country's ghettos, smashing up businesses and rounding up Jews. The barber ends up in a concentration camp, from which escapes, just in time for Hynkel to suffer a mishap on a boat which ends with him in the camp and leaves the world with a serious case of mistaken identity.
The film largely consists of set pieces, featuring some of Chaplin's best physical comedy, much of it dialogue free as well, such as the graceful dance with the balloon, the hair raising plane ride to freedom, and the running gag involving confusion over the correct salute. Chaplin's reputation as a perfectionist is well deserved judging from the elaborate staging and construction of the scenes.
Special mention also needs to go to Jack Oakie, who plays a thinly disguised version of Mussolini, Benzini Napaloni, the ruler of neighbouring Bacteria. The state visit is an increasingly ridiculous exercise in one upmanship, with a misbehaving train carriage, uneven furniture, and a barber chair gag that predates the Bugs Bunny cartoon Rabbit of Seville.
The film only really comes unstuck at the very end, when the barber, impersonating Hynkel, takes to the microphone to deliver a heartfelt three minute monologue to the assembled crowd, both on screen and those sitting in the cinema. There is very little to find fault with in the content, a plea for kindness and humanity in the face of industrialisation and war, and a reassurance to those suffering under Hynkel/Hitler that freedom will eventually prevail. As a standalone piece it is certainly moving and stirring, however as part of the film, the speech jars with the style and content of that which has preceded it and moves towards the earnest lecturing Chaplin had avoided up to then.
Your perception of the film's success as a satire may depend on how you personally define satire. Other than the climax, rather than hand-wringing or over intellectualising Chaplin is more interested in showing Hynkel to be a stupid buffoon. He spent a lot of time studying and aping Hitler's mannerisms and speech patterns, and clearly wanted the audience to link their scornful laughter at Hynkel with their attitudes to Hitler. However, writing some years later in his autobiography, Chaplin said that could not have made the film if he had known at the time of the true horror of the Holocaust. While understandable, this would have been a great shame and a great loss to the world. Despots are invariably humourless, and fully deserve to have a raspberry blown in their faces. It may not bring them down, but it may make a chink in their armour, and sometimes, as Mark Twain once said, the human race has one really effective weapon, and that is laughter.