Here is your short paragraph on Nationalism !
Nationalism is a kind of state of mind which tries to make the nation with an effective unity. It has been the potent of making the new and modernized world.
Nationalism has caused disintegration of many empires and has inspired many for freedom. It has developed on a remarkable scale in the western countries and is now growing in the African countries.
Nationalism definitely serves as source of integration among the states, however it would fail when it denies the common interest of the people that binds one country to another. It is such situations that lead to political domination and territorial expansion.
In its actual form, Nationalism is pure and beautiful, however when not considered in the right manner, it may lead to serious outcomes among men of one nation to another. Nationalism these days only comes in the form of placing ones country over the other and not considering humanity, thereby exploiting the weak in all aspects. It was this same spirit of nationalism that gave rise to the two great world wars that led to the loss of life for millions.
Hence it has come to a situation where a new concept is allowed to grow which builds in good relations between the people of both the countries. With a country like India, having many states, nationalism is indeed great, provided there be no fights against each other for borders and land.