All good points and I will add Indian Muslims and Rohingyas to the mix.
Pakistan has already started fencing the Afghan border. Afghanistan is important to Pakistan ( far more important than Bangladesh! ) but we need to keep the Afghan's happy instead of riling them up.
Afghan was the only country that did NOT recognize Pakistan when it was established in 1947, outdoing even our Indian friends. I also favor a carrot and stick policy with Afghanistan. Any attack from Afghan soil on Pakistan must meet with a befitting response. I am glad Pakistan has developed drone capabilities to deal out the punishment and the Super Tucanos
of the AfAF will be dealt with just as we dealt with their Su-22s and Mig 21s earlier.
I am amused at PDF posts here imagining Assamese Muslims, Bangladeshis and Indian Muslims will fight for the "Ummah "
The Germans tried this trick in Yugoslavia hoping to turn religious and ethnic divisions to their advantage. They armed Catholic Croats and Bosnians against Slavic Serbs ( Cetniks) hoping to disable the Communist Soviet supported partisan resistance under Tito. The move failed because no matter how well armed a minority remains a minority and is ultimately overwhelmed. Pakistan's attempt to arm Chakmas and get them to fight the Mukti Bahini in Bangladesh ended in a disaster for the Chakmas leading to a carnage and displacement. India attempted the same arming and training the Chakma Shanti Bahini to fight the Bangladesh Army with more success because unlike 1971 the Chakmas now were fighting under Indian patronage and had safe havens in India to train and recoup losses. The Jews in the Warsaw ghetto were secretly armed by the Allies , and rose up against the German Nazi occupation in the summer of 1944 and were slaughtered by the Germans. The Polish population with latent anti- semitism did not help. Pakistan also armed a small group of "Biharis" ( refugees from India's eastern provinces) to fight the Mukti Bahini in 1971. These "Biharis" paid a fearful price. Most fought to the last bullet and last man for Pakistan, their last battle being the Mirpur bridge which controlled the access to the Mirpur refugee camps. In a different battle some were captured wounded but still alive, and dragged to an island on the Padma river where they were bayoneted by the Mukti Bahini. A LIFE magazine photographer vividly captured the event on camera and published his award winning pictures. Forum rules prohibit such uploads but a search in Google on the line "Mukti Bahini Gurillas bayonet Biharis " will reveal some very historical pictures.
No minority can survive in a hostile majority environment no matter how well armed.
Bangladesh in a larger sense is a "minority" in a much larger majority India. Risking a war with India on behalf of Pakistan is the last thing on the minds of the Bangladesh Army which suffered heavy casualties even when fighting Shanti Bahini Chakmas.