The migration variable is particularly interesting because the right-wing fundamentalist Wahabi sect of Sunni Islam gained strength in Saudi Arabia in the late 19th century and has had an increasingly strong influence on Muslim attitudes as oil money as vastly extended the reach of Saudi thinking. Note that the migration referred to is largely economic (cheap labor) rather religious pilgrimages to Mecca. The article notes that a much larger fraction of Pakistanis migrate to the Gulf than do Indians and that helps to explain at least some of the difference in the more hardline attitude of Pakistanis compared to those living in India. However, both of the demographic influences on moderation are vulnerable to change:
Rising literacy, an ever-more urban population and growing wealth and information may yet encourage more extremist factions to emerge. Large migration flows to the Gulf might yet help to bring back more conservative Islamic beliefs and funds for Wahhabi mosques and madrassas. Similarly, if Hindu nationalists in power were to grow heavy-handed, a backlash and a rise in extremism are easy to imagine. The stability in India is a remarkable achievement. With luck, zealots and murderers such as al-Zawahiri will therefore fail in their desperate ambitions. But preserving stability will be a task for everyone.