Hello,
I am not a BD member, but yes, I am a humble student of Pakistans history. As far as 1971 episode is concerned, that is true that both, the West and East Pakistans politicians were responsible and I would put the blame equally on the two parties. West Pakistan is more responsible because it was not only the politicians but the military and civil bureaucracy was also responsible and much more than the politicians.
You may choose to disagree with me, but allow me to say that East Pakistans demand of Bengali as the second national language was not correct (at least at that time). Lots of politics was played on this unnecessary issue. There is no doubt that Bengali was the single most spoken language in the united Pakistan (owing to the largest population of the East Pakistani Bengalis), but Bengali was not widely spoken or understood in the West Pakistan. Contrary to which, Urdu was spoken and understood in both, East as well as West Pakistan. Additionally, Urdu was a neutral language, as it was not the language of any ethnic population of the United Pakistan except for those who migrated from the Muslim majority areas of British India. To this day, I am failed to understand why East Pakistanis took the language issue so seriously. There is no doubt that Bengalis (both on the East and the West Bengal) love their culture and admire Bangla Bhasha more than any language.
Contrary to this, in West Pakistan, the Urdu was readily accepted in particularly by the Punjabis. No province played more important a role in the development of Urdu language in West Pakistan than Punjab. Most notable literary work was undoubtedly done by the people from Punjab albeit of the fact that Urdu was not their mother tongue. I heard from many older folks that in Karachi (where Urdu speaking mohajirs are in majority), a barbershop would have a signboard in English such as Hair cutting salon, while in Punjab (where fewer Urdu speaking mohajirs lived), it would have a signboard in true Urdu language Zulf Tarash.
Anyway, all I am trying to say is, the language issue unnecessarily stirred up the pot, and caused lots of misunderstanding between the East and the West Pakistan. The issue of language and so early in the life of Pakistan did lots of damage. It was from that point onwards, an antipathy developed against the East Pakistanis in the West Pakistan.
Than of course there were legitimate issues such as the underrepresentation of the East Pakistanis in virtually every department especially in the civil services and the armed forces; uneven distribution of resources (the financial problems got worse time to time due to the floods, and cyclones which frequented Bay of Bengal) etc. These problems could have been resolved if there was some continuity of the democratic process, but alas, first Iskander Mirza hijacked Quid e Azams Pakistan, and after him, Ayub and Yahya. In reality, during Iskanders and Ayubs time, there existed virtually no political process, and all was literally a one-man show.
The 1965 war unveiled the vulnerability of the East Pakistan against any possible attack from India. There is no doubt that the realization of this vulnerability eventually emboldened India and the separatist elements (who existed long before 1971 because of the language plus other issues) who knew that if East Pakistan was ever attacked internally or externally or combined, the West Pakistan would never be able to defend it due to the geographical separation of the two wings.
Bhutto is the most misunderstood (at least in my opinion) person; he was blamed for the separation of the East Pakistan not only in the East Pakistan, but as much or perhaps more in the West Pakistan. First of all, Bhutto became a true leader and a politician only after the 1971 debacle. He started his career in the time of a dictator, Iskander Mirza; eventually reached to the post of the foreign Minister in the time of another Dictator, Ayub Khan. During all this time, he was not a politician but a very shrewd bureaucrat who could feel the pulse of the time. Bhutto was so close to Ayub Khan that he used to call him Daddy. It was only after the 1965 war, when Ayub realized that Bhutto was not that intelligent and foresighted as he used to present himself. After the war, Ayubs fall was already started, and no one knew that more precisely than Bhutto, his foreign minister. Bhutto was approached by the Americans who were also through with weak and useless Ayub, and proposed him to establish his own political party. Bhutto left Ayub, came into public and lured them telling about the half baked stories of Tashkent agreement. The iron was red hot, people were fed-up of failed policies of Ayub and ever increasing inflation in Pakistan, and embraced Bhutto as their new hope. Pakistanis never realized that Bhutto was not one of them, he could never be; he had a feudal background, was literally raised and groomed by the Military Dictators, and who had started his party (PPP) with the advice and support of the American CIA.
The 1970 national elections
Awami league took the majority seats in the national assembly, followed by Pakistan Peoples Party which arose as the majority party in the West Pakistan. All Yahya had to do was to invite the leader of the majority winning party to form the Government. He did not fulfill his duty, instead his refusal paved way for the demonstrations in the East Pakistan. He may have been under pressure by Bhutto, but could Bhutto force him not to invite Mr. Mujib to form the government? I do not think so. Yahya was not a weak president; he was the Army Chief, who had full support of the Army. If he had invited Mr. Mujib to form the Government, what Bhutto could have done? Gone on the streets? On which issue? That a majority winning part was invited to form the Government? I do not think that it was possible for him to bring the people on the streets following an illegitimate demand. So the blame does not fall as much on Bhutto as much it falls on Yahya Khan. Again, it was not Bhutto who unleashed the military might on the East Pakistanis, it was Yahya, under whose direct orders Pakistan Army went on conquering its own country. Things would have never turned that ugly if the military operation was not conducted in the first place which simply resulted in a domino effect. Things were no longer in control of Mr. Mujib and his senior party members as ordinary Bengalis wanted to defend themselves against the indiscriminate military operation. Undoubtedly, atrocities were committed from both the sides largely as a desire to take revenge of the personal losses. It is not that only Bengalis were massacred by the Pakistan Army/Security forces, non-Bengalis were also killed by the activists of the Mukti Bahini, proportionately less because they were already in minority.
But as I said above, all this could have been avoided if Mr. Mujibs six points were considered favorably (none of which were non-negotiable), and if wisdom had prevailed over arrogance and racial superiority complex of the West Pakistans ruling elite class.