In general, no, Mesopotamia did not fall because of attack from other empires, since it was primarily due to the Tigris and Euphrates Rivers drying up that led to a lack of produce, and therefore a fall in the empire itself.
East Pakistan was the eastern provincial wing of Pakistan between 1947 and 1971, covering the territory of the modern country Bangladesh. Its land borders were with India and Burma, with a coastline on the Bay of Bengal. East Pakistanis were popularly known as "Pakistani Bengalis"; to distinguish this region from the India's state West Bengal (which is also known as "Indian Bengal"), East Pakistan was known as "Pakistani Bengal".
Hopes this helps
1) Santa Anna had signed a treaty to grant Texas independence and Mexico refused to accept this treaty.
2) Texas was bankrupt.
3) Comanches and Indian groups threatened attack smaller Texan communities.
