Tom Rogan writes for National Review Online that the Paris terror attacks ought to put one political argument to rest.

For the past 18 months, I and others have repeatedly warned that ISIS posed a special threat to Western nations. We were often accused of scaremongering or warmongering. But then came last Friday. And now that the war has come home — to the streets of a Western city filled with sports fans and music fans and individuals celebrating democratic freedom — the debate is closed.

ISIS is at war with the West. And it must be ended. Of course, in the days ahead some will argue that we should keep “Paris in perspective.” Consider this weekend’s erudite assertions by The Atlantic’s Conor Friedersdorf, who cautions against French retaliation because “ill-chosen wars can and do carry more costs than benefits.” This logic is grossly mistaken. Today, as surely as at Pearl Harbor, the choice of war has been imposed by the enemy.

From the relative sanctuary of its caliphate, ISIS has now invaded the West with arrogant glee. And although some will say that the terrorist threat remains small — that more people are killed by umbrellas than by terrorist attacks — this single attack of terrorism is an onslaught against our societal fabric. By murdering a range of individuals in a range of social settings and in a range of ways, ISIS is cultivating the belief that our lives are insecure.

Not everyone will agree with Rogan. But the evidence for his argument is stronger than evidence within other areas of public policy dispute in which one group contends the debate is settled.