These days we don't have leaders. We have politicians for whom politics is a profession. These people don't know anything except dividing people. They cannot do any other business. Politics is bread earner for them. It also keep them safe from the consequences of their felonies and crimes. These shameless people know that public can be motivated by exploiting its emotion. So, they use such words and use such language which instigates a sense of pride or sense of hatred in the minds of people. They create false enemies. Nationalism is a common word for them. They use this word to mark their opponents as the enemy of the nation. In this way they can trample anyone who comes in their way.
But in my view public is the worst enemy of its own. I will not blame everything on politicians. They are doing what their profession demands from them. Can you expect a butcher to be merciful? How will he earn if he become non-violent? So, politicians are just like butchers who are working for a defined goal but I will blame the public for this sorts of things. Why it become follower of corrupt politicians? Why it blindly follow and support anything what politicians tell? In any form of government nobody can rule without the consent of the public. Why public send their sons and daughters in armies? Why armies are revered? Just to keep people slave?
This situation is present in every country and blind nationalism (jingoism) is the root cause of this problem. Especially in democratic countries no politician can be more vicious than the public.