The German Chancellor Otto von Bismarck, mastermind of the German unification, and the charismatic dictator of the Third Reich, Adolf Hitler, were similar in many respects. Both were brilliant statesman, masters of manipulating the interests of others in order to achieve their goals. Both practiced realpolitik, willing to backstab, connive, and use blatantly illegal methods to gain power and prestige, both for themselves and for their nations. Both were loyal to a fault to their native lands. And both showed their policies to be dominated by a single, overarching goal for the entire time they were in power.
The differences between these two statesmen, though subtle, are significant. These differences are what caused one to be remembered as charismatic, a brilliant leader, and one of the most successful statesmen in history, and the other as repugnant, demonic, and one of the most evil statesmen ever. These differences are, for the most part, simply differences in degree of the characteristics mentioned above. Summed up, Bismarck knew the appropriate place to stop his policy for the good of the nation, and Hitler did not. Where Bismarck was content to be chancellor and control the nation from behind the scenes, Hitler had to be Der Fuhrer, personally ruling all aspects of the nation with an iron fist. While Bismarck stopped his conquests after reasonable gains and concentrated on strengthening Germany domestically, Hitler attempted to take over the world. And, while Bismarck adopted some oppressive laws in order to strengthen the nation, he never would have committed genocide for these purposes, as Hitler did, killing millions of minorities in concentration camps during his rule.
Bismarck and Hitler came from similar schools of political thought. Both were utterly ruthless in the elimination of their political enemies in order to concentrate power in their own hands. Bismarck often passed laws in order to suppress the growth of parties and groups he saw as dangerous. In the 1870s, in response the the Syllabus of Errors, a Catholic document directly attacking many institutions important in Germany, Bismarck expelled the Jesuits, closed church schools, and removed subsidies for the church. In 1878 he forced a law prohibiting socialist political parties through the Reichstag because they often opposed him. Hitler also systematically eliminated his enemies, although in a much more direct, brutal fashion. On the "night of the long knives" in 1934 SS men, on orders from Hitler, killed hundreds of members of the SA, Catholic action, as well as prominent statesmen such as General Kurt von Schleicher and his wife. The difference between the two men on this point was the brutality with which they carried out their purges — Hitler did so with shocking and unneeded violence, and Bismarck used at least some moderation.
In terms of foreign affairs, both men acted as one would expect after reviewing their domestic policies — brutal, sneaky, underhanded, Hitler acting such to a greater extent than Bismarck. Both were extremely aggressive, shattering all the former diplomatic and political standards and using realpolitik instead. Each would often make a treaty or give concessions, seemingly in good faith, when in reality already thinking about how he could profit by recinding the agreement in the near future. Good examples of this behavior are Bismarck's convenient "forgetfullness" about his agreement to allow Napoleon to take Belgium, his bewildering concession of Holstein (and with it Kiel) to Austria, and his subsequent attack on that nation, as well as Hitler's repeated agreements to stop annexing more territory, all untrue.
Each man had a goal important to him, which dominated all his policy decisions, related to the greatness of Germany. Bismarck was a prominent statesman in Prussia at the time when there was no united Germany. He attempted, through all his policies, to unite all the German states except Austria as a Prussian-led nation. In order to do this, he was willing to implement any neccessary domestic policy, go to war multiple times with powerful nations, and sacrifice almost anything. Hitler, too, was a tremendously nationalistic German patriot. He had been wounded in the first Great War, and Germany's defeat had been the low point of his life. He never wanted to see Germany reduced to such a state again, and in fact wanted to dominate the lands of the old Holy Roman Empire (the First Reich) and beyond. For this, he violated most every term of the Treaty of Versailles, sacrificed millions of his countrymen in the battlefields of the Second World War, and killed millions of Jews and other "undesirables" in concentration camps. Again, the difference between Bismarck and Hitler on this point was one of degree — Bismarck's goal was a reasonable one, and once he had achieved it at long last, he continued to better Germany through other means. Hitler, on the other hand, had such a huge, unreasonable goal — nothing less than complete domination of the western world — that he had to resort to many more outrageous and shocking methods to do so, such as his blood purges, his war against the Allies, and his murders of millions he believed to be useless to society.
Bismarck and Hitler were similar in many ways. Their goals, reasons for these goals, and methods used to achieve them were very similar. Their difference, an important one causing each to take his respective place in history, seems relatively minor — the degree to which each was willing to discard all morals, all sensibilities, in order to achieve their goals at all costs. These differences, however, are what cause history to turn out the way it does. If Hitler had lived in Bismarck's time, and Bismarck in Hitler's, these minor differences would cause us to be reading a completely different history book today.