Answer:
Pakistan lost its eastern wing on December 16, 1971, but the seeds of discord were sown much earlier. It’s not possible to pinpoint what led to the dismemberment of Pakistan and why the Bengalis who played a pivotal role in Pakistan Movement opted for a separatist path, but there were some significant developments such as the postponement of the inaugural session, on March 3, of the National Assembly after the December 7, 1970 elections that led to the splitting of a country in 1971.
Following the postponement of this inaugural session of National Assembly till the launching of ‘Operation Search Light’ on March 25 to crush the civil disobedience movement launched by the majority party Awami League (162 out of 300 seats of National Assembly in December 1970 elections), East Pakistan existed as a part of Pakistan. Events taking place after the military operation, however, diminished the hopes to save Jinnah’s Pakistan from dismemberment.
Around 47 years have passed since a chain of events unfolding in March 1971 deepened the wedge and hostility between the two wings of Pakistan leading to their violent break-up. How the unilateral postponement of the National Assembly session acted as a catalyst to accelerate the disintegration of Pakistan, and was there a thought process at the national level to visualise the grave consequences, remain unanswered questions.