The Easter Sunday massacre in Sri Lanka was a game changing event for this nation that, pace its people’s hopes for peace and stability, throws the country right back into the precarity of violence that long has been a part and parcel of this country’s unfortunate experience. More globally, it signals that the war on Islamist extremism is far from over, and that letting our defenses down and/or neglecting the social and psychological determinants of extremism risks disastrous consequences.

Arie W. Kruglanski is Distinguished University Professor of Psychology at the University of Maryland, and a co-founding PI at START, the National Center of Excellence for the Study of Terrorism and the Response to Terrorism.

Malkanthi Hettiarachchi is a Chartered Clinical Psychologist, and a counterterrorism researcher and instructor.

Michele Gelfand is Distinguished University Professor and Professor of Psychology at the University of Maryland, College Park. Her book Rule Makers, Rule Breakers: How Tight and Loose Cultures Wire Our World was published in 2018.