Final answer:
German nationalism had both positive and negative effects on Germany/Prussia. On the positive side, it led to the unification of Germany and its economic growth. On the negative side, it fueled rivalries and conflicts that resulted in World War I.
Step-by-step explanation:
German nationalism had both positive and negative effects on Germany/Prussia. On the positive side, it led to the unification of Germany, which created a strong and economically powerful nation. Germany became a major player in European politics and had a booming industrial sector. However, on the negative side, nationalism also fueled rivalries and conflicts between Germany and other European powers, ultimately leading to World War I and the devastating consequences that followed.