The march in Paris on Jan. 11 will be remembered as a day when the world stood united against terrorism and for freedom of expression. The crowd and the symbolism it embodied are comparable to the Liberation demonstrations in 1944. The political, religious and cultural diversity displayed at Republic Square is a remarkable testimony to the strength of belief and hope in the face of bigotry and violence – a goal toward which we should all seek to contribute. But behind the glittering façade lies a more mixed picture of dwindling multiculturalism, social mistrust, militant secularism, cultural violence, religious extremism and terrorism. The Paris attack lays bare how fragile these concepts are today. The future of the old continent with its old and new inhabitants will be largely shaped by what meaning and substance they will take on. This will also be a decisive process for Islam-Western relations in the 21st century.Condemning and containing terrorism and hate speech at the same time is key to preventing future attacks. What is at stake, however, involves more than taking security measures. It requires exposing entrenched racism on all fronts.While the world was focused on condemning terrorism, the old-fashioned racists of the right and the left sought to condemn all Muslims. News Corp. CEO Rupert Murdoch became the subject of criticism after tweeting that all Muslims must be held responsible for the Paris attack. Murdoch's message was clear: the world's 1.6 billion Muslims are suspects until they kneel down and beg for forgiveness before the white masters.Many people of conscience from around the world reacted to Murdoch's Islamophobic remarks. Some apologized on behalf of white people. J.K. Rowling, author of the Harry Potter series, responded by saying that "I was born Christian. If that makes Rupert Murdoch my responsibility, I'll auto-excommunicate."The fallacy of Murdoch's logic is self-evident, but needs to be underlined: if all Muslims are responsible for terrorism, then every white, Christian Westerner is responsible for the horrors of the last century including the massacres of Native Americans, black slavery, the two world wars, the Holocaust, Hiroshima, the Vietnam war, the Bosnian massacre, and so on. By blaming the entire Muslim world, Mr. Murdoch and his like, such as Bill Maher and Sam Harris, adopt the same logic that al-Qaida and other extremist groups apply to the entire "Christian West". Discernment and subtlety are easily forsaken where Muslims are concerned.Hate speech and racism must be exposed to the same extent as al-Qaida terrorism. Muslim leaders, communities and religious figures should play a leading role in this process. No matter how much we underline that Islam is a religion of peace and does not condone violence, some people go on committing violence in the name of Islam. This must be fought against to the same extent as the anti-Islamic hate movements.The problem is that plain bigotry and hatred toward Islam and Muslims are defended as freedom of speech.The celebrated French philosopher, Voltaire, whose name emerged as a defender of free speech after the Paris attack, had no tolerance toward the Jews. Today no one wants to remember what he had to say about them in a letter in 1771: ''They are, all of them, born with raging fanaticism in their hearts, just as the Bretons and the Germans are born with blond hair. I would not be in the least bit surprised if these people would not someday become deadly to the human race.''Voltaire was as harsh and bigoted toward Islam and its prophet as he was toward the Jews. Lest one think that anti-Semitism was a passing thought in Voltaire's oeuvre, a year later he was all over the "Jewish question" again: ''You have surpassed all nations in impertinent fables, in bad conduct and in barbarism. You deserve to be punished, for this is your destiny.''This is plain anti-Semitism and no one would defend it as free speech. Charlie Hebdo seems to uphold the same principle. In 2008, Charlie Hebdo editors fired French cartoonist Maurice Sinet on grounds of anti-Semitism when Sinet wrote a column in Charlie Hebdo in which he insinuated that Nicolas Sarkozy's son will "go a long way in life, that little lad" after marrying a Jewish lady and allegedly planning to convert to Judaism. This linking of Jewish conversion to social success, no matter how satirical it is, is a case of anti-Semitism. While some French intellectuals criticized the magazine's decision, an anti-racist group took Mr. Sinet to court for his anti-Semitic remarks.Charlie Hebdo's stance against anti-Semitism is to be commended. Why not apply the same principle to anti-Islamic hate discourse? After all, anti-Muslim hate speech is as much based on bigotry and discrimination as anti-Semitism. And it does lead to violence as we have seen in the countless cases of firebombs, arson attacks, killings, vandalism and discrimination in Germany, France, Sweden, Greece, Bulgaria, the U.S. and elsewhere.Furthermore, the Charlie Hebdo cartoons about the prophet of Islam are not satirical, but rather are bigoted and racist, and they target the sacred values of a minority community in Europe. But some people want Muslims only to condemn terrorism, to apologize for it and never raise their voice against anti-Muslim bigotry and discrimination.