Why did killings of protesters lead to further demonstrations in Iran?

During the 1978–1979 Iranian Revolution, the killing of protesters by government forces fueled a cycle of violence rather than suppressing dissent. In the context of Shiʿi Islam, where martyrdom holds profound religious significance, these deaths served to galvanize the opposition.1

The cycle was sustained by the Shiʿi tradition of commemorating the 40-day milestone of mourning for the deceased. These memorial services frequently evolved into new demonstrations, which in turn resulted in further casualties, creating a self-perpetuating momentum of protest and mortality. As the regime vacillated between concession and repression, these demonstrations—uniting secular and religious factions—were increasingly framed by the revolutionary rallying cry Allāhu akbar ("God is great"), ultimately contributing to the collapse of the shah’s regime.1