Modern India evolved out of the transitionary Dominion of India which was created from territories of the Britsh Raj.Bhutan was not the princely state under British government. In a 1924 decision, the Goverment of India resolved that while Bhutan ... read more
) was re-examined by London in 1932 as part of the issue of the status of India itself. It was decided to leave the decision to join an Indian federation up to Bhutan when the time came. read more
In any case, 1947 Nepal was a separate administrative identity, much like Sikkim, Bhutan, and Sri Lanka, or even Burma for that matter. Princely states fell right into India's geographic area, and were administratively dependent on India as well. Joining the union was the only option for them. read more