To unite most of the people must have same goal, same understanding, same religious belief or same level of education. Religion and Nationalism is a adamantium wall that prevents ever being combined and forming united states.
Although India might want to invade and take control. Many life will be lost, but eventually very big population of Muslims in India will find unity with Bangladeshi Muslims and break the country into pieces. So many Muslims will die in the conflict, so many will be killed, jailed, raped and vanished. But they are just way too big as population and become much bigger if combined. Muslims will have stronger force in combined India. And with the intolerance we have in our country and the fundamental Hindus in India, it will be a complete chaos.
It will be like Sudan. Current India will become much weaker. Also other forces like Russia, China and United States will fuel the conflict and turn it into a massive civil war. Only God, Allah or Bhagban knows how long will that last.
To unite, next generation have to be more receptive and more understanding, and more philosophic and less dismissive. Also they have to have the ability to think beyond their own religious beliefs and understanding of others’ opinions. And also most of them have to have that proper understanding of living in a benefits of United States. Government and their people has to be more giving than receiving. Indian government gave us nothing. They didn’t honor any agreements our country have with them, specially when it comes to controlling river water flow. We would also require something like a one religion or one belief system like Secularism and it has to be popular otherwise every effort will fail miserably.