Nationalism is important because people have naturally organized themselves into groups with common interests and goals ever since the start of human civilization about 12,000 years ago, and were probably doing it even before that. People who speak the same language, share the same ethnicity or faith, or happen to be like-minded politically, or any combination of those things, MIGHT want to have their own country and a government of their choosing, which represents the things they wish to preserve, EMPHASIZE, and grow. This can happen in any number of ways, for any number of reasons: The United States of America was formed as a Republic BASED on the concepts of Classical Liberalism. We have generally welcomed people from all around the world who wish to help us build a nation on those principles. The State of Israel was formed as a nation-state for people of the Jewish religion and ethnicity, so they could have a safe and secure homeland. The Union of Soviet Socialist Republics was founded as the world’s first nation-state based on Marxist theory. When their implementation became a failed experiment after roughly 75 years, the multi-ethnic USSR broke up into various nation-states based on the ethnicity of the people in each region. Between 1859 and 1870, the various peoples of the small states that MADE up the Italian ethnic and linguistic community all overthrew their governments and united under one, becoming the modern nation-state of Italy. The Republic of Kosovo seceded from Serbia in 2008 on the basis of self-determination for the MAJORITY ethnic Albanian population of that region.Explanation: