I wouldn't really consider it "Bengal's history", it really had nothing to do with Bengal in the first place as it was an internal matter. Politics is a dirty game in Bangladesh and after 1971 things went pear shaped. I do agree about the past (1000 years) most foreign invaders found it hard to come into Bengal because of our terrain. Bengali people are very agile and athletic when it comes to marshy terrain. The Islamic rule in Bengal wasn't really violent most foreigners were awliyas and daee's (spread the message of Islam) but we did go through turkic invasion. After 1500 Bengal especially East Bengal came under many different Islamic rule.
If you think about it, out of the 3 countries, it was only Bangladesh that went through invasion. The Indo-Pak beef was always battle of the greatest, it was just a point scoring game. I mean the population was intact whilst Bangladesh went through a full invasion and this is the modern period we are talking about.