Why is Pakistan a Muslim country?

Answer 1

It is a Muslim country because majority of its people are Muslims.

If the question is asking historically, the earliest Indus River Valley inhabitants were polytheists and the conquest of their civilization by the Aryans of the Caucasus Mountains in 15th century BCE and led to the creation of the Hindu Sacred Texts and the religion of Hinduism. Hinduism prevailed as the religion in what would become Pakistan until the Umayyad Caliphate conquered the province of Sindh and introduced Islam to the region in the 700s C.E. Over the next 1100 years, a parade of different Hindu and Islamic Empires ruled over parts of the Indian subcontinent so that by the 1930s, the Indian Subcontinent (British Colonial India) was roughly one-third Muslim and two-thirds Hindu with the primary concentration of Muslims where Pakistan and Bangladesh are today.

Muslim leaders in British India, like Muhammad Ali Jinnah, were afraid that should India become independent it would be a Hindu-dominated state that would actively perscute its Muslim citizens. As a result, they proposed that an Islamic State of Pakistan would be created in the areas where Muslims were most densely concentrated and the rest would belong to an independent India. While leaders like Gandhi disagreed, the Indian Hindus, like Jawaharlal Nehru accepted the partition. As a result Pakistan came into existence as an Islamic State, in the sense that it was for Muslims as a constituency/ethncity, not a religion. However, with the presidency of Zia ul-Haq, Pakistan has become more Islamist, incorporating parts of Shari'a into Pakistan's legal tradition.

Answer 2

Muslims came to Pakistan because it was made for them.