How do we 'liberate' ourselves from our own country? It's like saying that Rajshahi or Barishal should liberate themselves from Dhaka!
And about Bengali ethnicity, the people of West Bengal along with the Bengalis of Tripurs, Assam, etc. are the real unadulterated Bengalis....the flag-bearers of Bengalis in the world.
And as claimed by the Bangladeshis themselves, Bangladeshis are just foreigners from ME states living in Bangladesh and speaking Bengali because of living here for a considerable time. Even you are a Bengali-speaking foreigner settled in Bangladesh, as stated by you only!
And how are you supposed to do that?
And we are 1.2 billion btw!