i think it more of a problem created by India as a part of undeclared hegemony that it wants to maintain in its neighborhood. While they cross indian land on their way to nepal it did not do anything,,,but now when they want to go back it is posing as the strongest barrier.. For those who know bhutan well, it is nothing more than india's puppet too(indian academic curriculum, indian board exam, indian currency,india issued ID( i guess they dont have official citizenship certificate))... Otherwise Bhutanese govt is not that mighty to drive out all those people..(it's only a matter of speculation whether india ever pushed bhutanese govt to drive those refugees out of bhutan)