@El Sidd
Well, today global variables are different than let's say 120 years ago. With UNO and international laws, passport system, clearly defined and internationally recognised borders, trade agreements are those external factors that try to keep the countries intact in their form and suppress the dissenting voices. Otherwise fault lines exist and it is amusing to say even in EU, Scotland is not very happy to be part of UK, but the modern international laws discourage them, Catalonia thinks Spain is sucking on its resources and wants to separate, same goes for Bavaria in Germany and California and few other states in USA, Quebec in Canada...but international variables support their federations. So there is less to credit for any internal variables and more to the external factors especially in India's case which is mumble jumble of overpopulated and underdeveloped urban centres and villages. Let the global variables change, you will see how ribbon untying and letting the content spread.