I'm writing a paper that expects me to take a stance on a person in history's legacy, and I choose Bismarck. However, the more research I do, it seems that his legacy is a mixed bag. I understand that he really started to introduce social welfare to the western world, and that he is almost single handedly responsible for the unification of Germany, but doing this required war against Denmark, Austria, and France, and his alliance system helped set the stage for WW1. So really, is his legacy one of mostly positives or mostly negatives? It seems to me that it was mostly negative but friends have argued that Germany today as a successful power could not exist with Bismarck.
EDIT: Thanks so much for the replies, definitely helpful!
Hi, no actual historian, but a german with a strong interest on history. I will do my best.
You are correct with your positives: He did introduce social welfare and had a huge part in the unification of germany. With your negatives not so much: The alliance system he built was there to isolate France. The turn away that was done after he was pushed out of office set up the alliances as they were before WW1. If he had been there longer (or his system because he would have died) WW1 would not have happened. When he was in office a cordial relationship with Britian and Russia was still in place (historically then there was more enmity between them and France than with Germany having defeated Napoleon together with us). Because Germany under Bismark didn't yet go for colonialization there would have been no cause for problems between Germany and Britain.
The wars with Austria and Denmark have to be seen differently than the one with France. Austria was a war for the lead in the german south, Denmark over a stretch of land inhabited by both germans and danes. These could be called growing pains of a unification, not pretty but unavoidable.
France is a different story entirely. France had taken stretches of german land in Napoleons time, now there was a big unified new neighbour in the east that was never a challenge before. France rightfully feared for their domination on the continent. Germany as a proud new nation pushed for a leading european role. That war was fought, at least partially for pride. This is certainly one of the negatives, but was needed to finish up the unification (done in the mirror hall in Versailles).
In german history he is seen as a wise elder statesman (especially with his alliance system that kept France isolated for 20 years), not unlike Churchill. Hard when necessary, but not as someone who wasted away lives.