Again, you Indians cannot think things through clearly.
BD is not currently hostile to India but it may become in the future.
All that matters is finally BD has the funds to create a decently powerful military and it looks like it could well build it.
Bhutan can NEVER create a military that can be any threat to India.
India will have to readjust both it's foreign policy and it's defence posture to take this into account, especially with a BD that will inevitably display a more assertive foreign policy as it becomes richer and more powerful in the future.
The fact that Bangladesh
may become hostile in the future is predicated on the presence of core disputes between India and Bangladesh.
Like India and Pakistan have a core dispute regarding Kashmir.
India and China have a core dispute regarding Arunachal Pradesh.
India and Bangladesh have no core disputes. India and BD have already demarcated the land boundary agreement mutually. India still has to get it ratified by its Parliament, but for all intents and purposes, both India and BD have agreed on what each of them is willing to settle with. India being a generous party willing to cede an extra 10,000 acres of land to Bangladesh.
In the absence of such a core dispute, any hostility of India towards BD or BD towards India would remain temporary or passing. Certainly not even close to what is required to start putting their respective military on their borders.
That was the political aspect.
Now let us consider the military aspect.
1. With a land area that is smaller than Pakistan and a population that is equal to Pakistan in a region that is frequently hit by natural disasters
and without the billions of economic and military aid that Pakistan gets annually and the constant diplomatic support of USA and China - it would be unlikely that Bangladesh would have the resources to raise a military that is equal to Pakistan's despite being able to make an economy as big as Pakistan's in say a decade and a half or two.
2. Even if Bangladesh were able to raise a military as big as what Pakistan fields today...Pakistan's military is not at all impressive or formidable in comparison to India without the threat of nuclear weapons.
So
even if Bangladesh manages to make a military that is the equivalent of what Pakistan has now after a couple of decades, Indian military would still not consider it as a major threat by even today's Indian standards!
3. Let alone the fact that in a couple of decades India would have grown further and added more military muscle than the rest of South Asia put together.
Let me put it in simple terms - India of today can easily beat a Pakistan sized military of Bangladesh a couple of decades from now. Think what kind of military India would have of its own a couple of decades from now.
The bottomline -
Unless Bangladesh were to get nuclear weapons - regardless of what they add up in their economy and military, they would still never be a military threat to India.
And Bangladesh cannot get nuclear weapons because it has signed the NPT. If it tries to violate that, then it would be put under sanctions like Iran - and all those exports - which form the basis of Bangladesh's economic growth would evaporate the next day.
Sorry, but Bangladesh can never be a threat of any kind to India.
EDIT: With Bangladesh choosing to go the other way in its development - ie BD focusing on increasing literacy and employment in its country, it would lead to a more peaceable state unlike Pakistani population which is militaristic and jehad oriented because it is illiterate and without social safety.
Such a peaceable,educated and developed population automatically precludes rhetoric based opposition and war mongering . Ofcourse this is not the case now, but seeing BD's direction, it will be so in a couple of decades.