What affect did nationalism have on European affairs?

Nationalism affected Europe during the 19th century by making Europeans feel superior to other countries and governments, which led to the unification of both Germany and Italy, with Russia moving towards modernization and with France moving towards liberalism. This sense of superiority led to a stronger sense of unity between the peoples of each country and to a desire for increased military power which then, in turn, led to an alliance system between the European nations.