A girl takes a picture from the banks of the...

A girl takes a picture from the banks of the River Seine of the illuminated Eiffel Tower in the French national colors red, white and blue, Wednesday, Nov. 18, 2015. Credit: AP

As the magnitude of Friday's reign of terror in Paris became apparent, the realization began to set in that we are witnessing a watershed moment in the war on terror. In recent years, that term itself has often been treated as obsolete. The barbarous Islamic State -- ISIS -- was terrifying, but it was far away. This time, 129 people died in several coordinated attacks in the heart of Paris. That hits too close to home.

The day after, Republican presidential candidate Sen. Marco Rubio termed the tragedy "a wake-up call" to our "civilizational conflict with radical Islam." On the website of the Atlantic magazine, liberal pundit Peter Beinart criticizes Rubio for calling this conflict a "clash of civilizations," which he says equates all Islam with terror. Perhaps Rubio could have chosen his words more carefully, but this is indeed a war for the future of civilization. ISIS wants to remake all Muslim cultures in its radical fundamentalist image and build a caliphate to rule the world. It may not have a chance of succeeding, but it can make the world a much darker place on this quest.

Predictably, the Paris events have renewed the debate over Islam and terrorism -- and this debate remains frustratingly stuck between "Islam is terrorism" and "terrorism has nothing to do with Islam." Many on the left seem more concerned about an anti-Muslim backlash than about terror casualties. In a particularly bizarre display of myopia, just a few days ago the University of Minnesota student assembly killed a proposal for an annual commemoration of Sept. 11 because of fears that it might fuel "Islamophobia and racism." Meanwhile, many on the right seem to forget Muslims are the primary targets of Islamist terror.

While numerous Muslim scholars and clerics have condemned ISIS, Islamic texts provide some foundation for its extremist vision. It's not the only interpretation of those texts, but it's not a hijacking by interlopers. Moreover, far too many Muslims who are not followers of terror groups, including clerics sometimes praised as moderate, embrace ideas hostile to religious and personal freedom.

The hope lies with Muslim reformers such as British activist Maajid Nawaz, who get shamefully attacked as "Islamophobes" and sellouts by Western leftists such as journalist Max Blumenthal. But the Islamic reformation advocated by Muslims like Nawaz and secularist ex-Muslims like Ayaan Hirsi Ali is a long-term project. How do we deal with Islamist extremism and terror in the meantime? Calls for ruthless war are emotionally satisfying, but we know all too well that military action can have unforeseen consequences.

While the terror cell behind the Paris attacks may have been destroyed, we are certain to see further moves to tighten security -- and those measures will themselves pose a challenge to the West's civilizational values. Where do we draw the line between provocative but protected speech, and jihadist recruitment and incitement? When is surveillance justified, even if it intrudes on the exercise of religion? (There is an all-too-real record of extremists operating through mosques.) How should we balance compassion for refugees and a liberal border regime against the risk of terrorist infiltration? Libertarian idealism may be attractive to many -- myself included -- but the more vulnerable we are to terror, the more fragile general support for civil liberties will become.

If nothing else, the Paris attacks are a reminder that in the near future, we will face very serious questions. Leftists preoccupied with insensitive speech on college campuses and rightists preoccupied with the gay menace can sit at the kids' table and leave the public sphere to adults. "Safe space" suddenly acquires a whole different meaning when you know you could get shot or blown up while attending the theater or having dinner.

Cathy Young is a regular contributor to Reason magazine and Real Clear Politics.