How did nationalism lead to the creation of new countries in europe

Nationalism led to revolts because people were so proud of their own culture that they couldn't see past differences in other people. After Prussia defeated Austria, they gained control of the North German unification. But pressured by the Hungarians, he split into two independent countries because of differences. In Russia, there was a break down of the old czar empire because there were many nations that each had their own country. To control this diversity, the Romanov dynasty instituted the policy of Russification which actually strengthened nationalistic feelings, disunifying Russia. In the Ottoman empire, equal citizenship was granted and they massacred Armenians. But, it did bring the French people together