The attack in London that took the lives of four people, including a police officer, a mother, and the assailant himself, and injured nearly 40 followed the familiar and sad pattern of terrorist outrages that have rocked western civilization in recent years. A man described as “Asian” mowed down dozens on Westminster Bridge, jumped out just outside the halls of the British Parliament, stabbed a police officer, and then was finally gunned down. The mourning, the defiant speeches, and the questions remain in the wake of the dead and the maimed.

One of the sad truths of the 21st Century is that anyone at any time can be a victim of terrorism.

Groups such as ISIS and Al Qaida can inspire a group of or even just one sick individual with suicidal hate. Then people who have just gone out to dinner, visited their favorite club, attended a holiday party or, as in the case of London, are only walking down the street have their lives ended in horror.

Waging war against an ideology that promises the joys of paradise if one commits mass murder is the most vexing problem of our age. How does one stop people from doing that, short of rounding up anyone who fits the profile of a potential terrorist and sequester them from everyone else, a solution that any just society must reject? Mass murder is wrong in any circumstance. The slaughter of many innocents in the name of religion is blasphemy in any faith.

Currently, a loose coalition of forces are being gathered against the Islamic State, the little area of human-made Hell, and will in short order end it. But the coming campaign of liberation is not likely to end the idea of the Islamic State. Mad men will continue to be inspired to kill and die in service of something that civilized people can barely understand not to say agree with.

The only way to put an end to mass murder acts of jihad is to make the idea of such acts universally abhorrent. How to make such a revelation happen is one of the burning questions of a sordid, bloody century.