Answer:

In 1971-72, Bengali Muslims created the nation of Bangladesh.

Background:
The formation of Bangladesh was a result of the Bangladesh Liberation War, which took place between March and December 1971. The war was fought between East Pakistan (comprising predominantly Bengali Muslims) and West Pakistan (dominated by Punjabi Muslims), with the aim of achieving independence for East Pakistan.

Causes of the Liberation War:
1. Political Suppression: The people of East Pakistan, who were predominantly Bengali Muslims, felt marginalized and oppressed by the government of West Pakistan. They faced political suppression and economic exploitation.
2. Language Issue: The movement for independence gained momentum after the government declared Urdu as the sole national language of Pakistan, ignoring the majority Bengali-speaking population of East Pakistan.
3. Cultural Differences: The cultural differences between East and West Pakistan, including language, customs, and traditions, further deepened the divide between the two regions.

Course of the Liberation War:
1. Protests and Civil Disobedience: The movement for independence began with widespread protests, strikes, and civil disobedience in East Pakistan.
2. Repression and Violence: The Pakistani government responded with brutal repression, leading to large-scale violence against Bengali civilians.
3. Formation of the Mukti Bahini: Bengali fighters organized themselves into the Mukti Bahini (Liberation Forces) to resist the Pakistani army.
4. International Support: The liberation movement received international support, with countries like India providing assistance to the Mukti Bahini and sheltering millions of Bengali refugees.
5. Military Intervention: In December 1971, India intervened militarily, leading to the defeat of the Pakistani army and the eventual creation of Bangladesh.

Creation of Bangladesh:
On December 16, 1971, the Pakistani army surrendered to the joint forces of the Mukti Bahini and the Indian army. This marked the end of the war and the creation of Bangladesh as an independent nation. Sheikh Mujibur Rahman, the leader of the Awami League, became the first President of Bangladesh.

Significance:
The creation of Bangladesh marked a significant moment in the history of South Asia. It gave a voice to the aspirations of the Bengali people and provided them with political and cultural autonomy. The war also highlighted the importance of self-determination and the right to national identity, inspiring similar movements around the world.

Overall, the creation of Bangladesh in 1971-72 was a result of the Bangladesh Liberation War, fought by Bengali Muslims against the government of West Pakistan to achieve independence and self-determination.