India did with the Khalistan movement. So is with the insurgency in Assam, especially and ULFA and BLT. However the insurgency in NE was not religiously motivated, hence was a little easy than Khalistan. NE still remains affected but these organizations are more interested in extorting money and nothing else.
The Khalistan movement is isolated within the Punjab..and is isolated to a percentage of the population based on religion. Not 95% of the nation.