Bangladesh will never truly be an independent country, it's just an unfortunate reality. China has attempted to enter Bangladesh, but considering how much trouble they've run into, it is telling just how much control India has over BD's internal politics and security. I'm of the belief that if India declared it would annex BD, Hasina and her government would publicly and quickly accept Indian rule, as it is, a puppet state currently serves India far more. I honestly don't think BD is going to remain independent through this century.
[Edit]: I suspect one of two things is going to happen in the future. A) fearing further erosion of its sovereignty, BD's miltiary will commit a coup. B) BD will accept Indian rule.
If "A" happens, India is likely to intervene militarily and politically.
If "B" happens and India takes over BD, India will likely face an insurgency, which it will likely face for decades, but will likely overcome eventually.
In all honesty , what you said is partially correct. While china has attempted to enter bd, it has never fully succeed simply because of A ) Indian Influence ( least likely), but mainly because of ---B) Because of Her ( china's) own lack of desire to get involved in BD simply because there is much bigger things for china to get involved in for her own benefit than tiny little BD.
Hasina and her govt or any govt in bd for the matter will not accept indian rule , simply because no one atleast publicly wants to downgrade themselves ie PM to CM . Its how we south asians tend to think.
But yes you are correct on this point that a puppet state serves india more. NO SITTING PM of india will want to increase the muslim population of India. Currently there is i thing 180 million indion muslims on top of that if u add another 180 million, it severly upsets India's delicate demographical balance. Since this is not the middle ages, an invading force simply cannot come in , kill anyone they dont like and simply turn the land into a province , no country wishes to soil their own reputation like this. IN this era if you wish to keep the country as a provience you will have to integrate them in your own country. Since inda or any country for the matter dosent or wont want to appear as a genocidal prick, i suspect it will have to do the integration part. Sadly that costs a lot of $ as BD is no singapore. hence i suspect there will be no invasion of BD from india ever ! at best india will create a north korea south korea type relationship with bd and just turn the border so nothing goes in or out of bd .
India may only invade bd for a short time if say an unfavarable govt to delhi comes to power , even then the invasion can be termed as an intervention. Invade , come in kill those who opposed you and leave. if india cant do that she will simply close the border with BD refusing to do bussiness. i think from US wars in iraq and afganistan we can see that fighting insurgency is costly very COSTLY. and US homeland was never hit simply because of the distance between us and her wars. But BD is right next to india and how much do you you think it will cost for the bd insurgency to spread into india ? very little. Makes more sense for india to simply close the border and make them sufffer.
ANd yes BD's military sooner or later will do the coup, but they wont do it without aproval and backing from either beijing or washington .
SO in a way you are correct, BD will never be a proper soverign country and will always be in either Chinese or Indian sphere of influnce .
I guess it all matters on who pushes ahead in the race between India and china. If the dragon continues her rise as we are seeing today, the day is not far when BD army will simply tell Hasina and CO to leave .