Nigeria, Nov. 1 -- For some Nigerian Muslim fundamentalists, the killing of Yahaya Masussuka prompted relief rather than grief. The reaction highlights a troubling problem in Nigeria's religious and security landscape: the growing tendency to rationalise or celebrate violence against people whose religious beliefs differ from those of their critics.

Over the past two decades, many prominent Islamic clerics, including Ja'afar Adam and Auwal Albani, have been assassinated in northern Nigeria. Some of their theological rivals celebrated or justified their deaths, arguing that the clerics had fallen victim to the same brand of extremism they had helped nurture.

Auwal Rafsanjani, the executive director of Civil Society Legislative Advocacy C...