Bangladesh is noted for cultural pluralism within a Bengali Muslim majority. Traditional Bengali secularism has been an important contributor to the nation's society and ethos. The Bengali language is a fundamental element of Bangladeshi identity. It is a secular language which evolved between the 7th and 10th centuries, with an indigenous alphabet, and unites people of different faiths and regions. The Bengali Language Movement sowed the seeds of East Pakistani nationalism, ultimately culminating in the Bangladesh Liberation War in 1971. Since independence, the relationship between religion and the state has been controversial. Between 1972 and 1975, Bangladesh experienced socialism under a secular parliamentary system. Military coups ushered a sixteen-year presidential regime, which restored the free market and promoted moderate Islamism. In 1988, Islam was made the state religion. In 2010, the Bangladesh Supreme Court reaffirmed the principle of separation of mosque and state in the constitution, although Islam remains the state religion. The government generally respects freedom of religion and ensures protection for minorities. Another debate on national identity concerns attitudes towards the Chittagong Hill Tracts. A low-level insurgency took place in the region to demand constitutional autonomy against Bengali settlements. Despite a peace treaty in 1997, the Bangladeshi government is yet to implement many of its commitments to protect adivasi land rights. However, the deletion in 1977 of Bangalee as the nationality term for the country's citizens, in order to be inclusive of non-Bengali minorities, also reflects attempts to build a more cosmopolitan Bangladeshi society.