Nationalism is one of those words that isn't all that easy to define. The problem lies in the fact it is often considered synonymous with patriotism. It seems that for a period in the past the words were in fact synonymous. While there continues to be some overlap, they certainly aren't the same and actually conjure up very different images today.
One of the key differences between nationalism and patriotism is that nationalism promotes a nation's supremacy over all other nations. Whereas patriotism is the love of one's nation without the element of exclusivity. A patriotic love of one's nation doesn't necessarily demand viewing it as superior to all others no matter how much you love it. Nationalism tends to promote the view of one's nation's superiority.
Just as you can tell something about a person by the company they keep, the same can be said for words, which is pretty useful when looking at words that are a little tricky to define. According to Merriam-Webster, the key difference between nationalism can be discerned by examining the most common modifiers for the two words. Merriam-Webster states how an examination of a large body of texts show that patriotism is often associated with such modifiers as "bravery, valor, and devotion," whereas nationalism is usually associated with "specific movements, most frequently of a political bent." There often appears to be a strong association with aggressive action when it comes to nationalism, whereas patriotism seems to be more to do with cherishing one's country and culture.
The Encyclopedia Americana states how nationalism has particularly played a major role in the world since World War II and explains how under Joseph Stalin, for example, techniques used under Hitler's regime were developed yet further. The same article also suggests, whereas in ancient times a person's supreme sense of loyalty would likely have been directed towards his religion, in modern times "this place has been taken by the nation.” Particularly in certain forms, nationalism has the features of a religion.
Nationalism is often seen as the driving force behind such militaristic movements and protectionist policies. There is little doubt that nationalism in its most extreme forms has led to some of the most terrible crimes in history which is not something so easily said about patriotism. Often times, nationalism is linked to feelings of racial superiority and is driven by feelings of superior ethnicity and often engenders feelings of hatred toward those who don't happen to come from the same ethnicity.
Clearly, there is a point at which patriotism and nationalism part company. While the one fosters a fondness for one's own country and culture while remaining open to others, the other is a driving force behind division, exclusivity, and hatred.
These two words are good examples of just how words change their meaning over time. Whereas they were synonyms at one time, clearly they aren't now.
Nationalism has accrued rather ugly associations and is often linked to deeply unpleasant events in human history. Patriotism, on the other hand, may bring to mind images of football fans cheering on their team during the World Cup. Clearly, the two words bring very different images to mind. This is worth emphasizing as the two are commonly conflated. Perhaps this is a result of their once being synonyms and the residual overlap.
How long have the words nationalism and patriotism been around? According to Merriam-Webster's website, the word patriotism dates back to the middle of the 17th century. It first appeared in print in the rather unwieldy titled Reasons Why the Supreme Authority of the Three Nations (for the time) is not in the Parliament, 1653, and in Thomas Urquhart's, Ekskybalauron, 1652.
On the other hand, nationalism doesn't appear in print until just prior to the 19th century, around 150 years after the word patriotism appeared. At the time the words were more or less interchangeable.
Some might think that such a formidable world power as the Roman Empire and the Holy Roman Empire might have demonstrated the concept of nationalism leading to the conclusion that nationalism finds its roots in antiquity. This isn't entirely so. The Roman Empire looked to establishing groups of nations under one banner so to speak.
Many historians point to later events in the 18th and 19th centuries such as the French and American revolutions as seeing the beginnings of nationalism.
With the likes of French Napoleon and Chancellor of the German Empire Otto von Bismarck asserting ever more nationalist ideals and greater unification, nationalism started to morph into something that began to accrue more toxic notions of racial supremacy.
A 1962 article in Time magazine pointed out a very interesting distinction between ancient and modern times. It described how the feudal lords of the Middle Ages would pledge allegiance and loyalty to the king. Not to the country or nation.
The same article conceded that nationality has always existed. Patriotism likewise has a long history, whether applied to a locality or extended to embrace an empire. However, the fusing together of both patriotism and nationality and the emergence of a sort of national patriotism which takes precedence over other forms of loyalty, which is nationalism, is in fact a modern phenomenon.
Groups, usually the family, live closely together and a form of belonging develops as does loyalty. As groups become larger, the gates are open for certain individuals to stir up feelings of their group's being superior to all other groups. Something akin to nationalism develops.
One professor of political science, Ivo Duchacek, in his book Conflict and Cooperation Among Nations pointed to the divisive nature of nationalism stating that it has serves to divide "humanity into mutually intolerant units. As a result people think as Americans, Russians, Chinese, Egyptians, or Peruvians first, and as human beings second—if at all.”