Sentence:  India being also at the forefront of the anti-colonial battle in the world, any official recognition of territorial limits for a would-be Pakistan on Indian territory could have led to the <WSD>Ulsterisation</WSD> of India. 
Meaning of the word marked with <WSD> tags:  The rise of nationalism in a region, and consequent rejection of traditional left/right politics in favour of nationalist/unionist politics.