[Daniel Pipes is director of the Middle East Forum and Taube distinguished visiting fellow at the Hoover Institution of Stanford University]

Who is the most important European alive today? I nominate the Dutch politician Geert Wilders. I do so because he is best placed to deal with the Islamic challenge facing the continent. He has the potential to emerge as a world-historical figure.

That Islamic challenge consists of two components: on the one hand, an indigenous population’s withering Christian faith, inadequate birthrate, and cultural diffidence, and on the other an influx of devout, prolific, and culturally assertive Muslim immigrants. This fast-moving situation raises profound questions about Europe: Will it retain its historic civilization or become a majority-Muslim continent living under Islamic law (the Shari’a)?

Wilders, 46, founder and head of the Party for Freedom (PVV), is the unrivaled leader of those Europeans who wish to retain their historic identity. That’s because he and the PVV differ from most of Europe’s other nationalist, anti-immigrant parties.

The PVV is libertarian and mainstream conservative, without roots in neo-Fascism, nativism, conspiricism, antisemitism, or other forms of extremism. (Wilders publicly emulates Ronald Reagan.)...

Although I disagree with Wilders about Islam (I respect the religion but fight Islamists with all I have), we stand shoulder-to-shoulder against the lawsuit. I reject the criminalization of political differences, particularly attempts to thwart a grassroots political movement via the courts. Accordingly, the Middle East Forum’s Legal Project has worked on Wilders’s behalf, raising substantial funds for his defense and helping in other ways. We do so convinced of the paramount importance of talking freely in public during time of war about the nature of the enemy....