Nationalism can be seen as both good and bad, depending on how it is used.
Good: Nationalism can create a strong sense of unity and pride among people in a country. For example, during World War II, many countries used nationalism to rally their citizens to support the war effort, which helped them come together and work towards a common goal.
Bad: However, nationalism can also lead to conflict and division. For instance, extreme nationalism in the early 20th century contributed to World War I and the rise of dictatorships, as some countries sought to dominate others. It can also lead to discrimination against people from different backgrounds, as seen in situations like ethnic conflicts in the Balkans in the 1990s.
In summary, nationalism can foster unity but can also cause division and conflict, so it is not inherently good or bad.