Wednesday's shocking terror attack on the French satirical journal Charlie Hebdo should finally awaken Western publics to the threat posed by radical Islamists to free speech worldwide.

That threat may seem obvious when 10 journalists from a newspaper that published caricatures of the prophet Muhammad are murdered by masked men with Kalashnikovs shouting "Allahu Akbar."

Yet these assassinations follow a rising number of death threats and violent protests by Islamic fundamentalists against Western books, films, or newspapers they deem offensive. Many Western observers have blamed the authors - for disrespecting Islam - rather than those who organize the violence.

Let's hope the Charlie Hebdo murders debunk that fuzzy thinking. Religious zealots can't be permitted to define the limits of our free speech.

That was the attitude of Charlie Hebdo, whose comic jibes spared no one. In 2011, the magazine's office was firebombed as it was about to publish a cartoon cover depicting the prophet Muhammad saying, "100 lashes if you're not dying of laughter."

"We want to laugh at the extremists - every extremist," staffer Laurent Leger said in a French TV interview in 2012. "They can be Muslim, Jewish, Catholic. Everyone can be religious, but extremist thoughts and acts we cannot accept."

"In France, we always have the right to write and draw," he added. "And if some people are not happy with this, they can sue us and we can defend ourselves. That's democracy. You don't throw bombs; you discuss, you debate. But you don't act violently." (Leger was wounded yesterday but survived).

Yet when Islamic fundamentalists repeatedly threatened violence for Western media portrayals of the prophet Muhammad, many commentators blamed the victims. These threats began when Iran's Ayatollah Khomeini issued a fatwa in 1989 calling for the death of author Salman Rushdie because his novel The Satanic Verses supposedly "insulted" Islam. Many Western critics labeled Rushdie a provocateur.

When the Danish newspaper Jyllands-Posten published cartoons of Muhammad in 2005, leading to deadly riots in several Muslim countries and death threats against the cartoonists, many observers blamed the newspaper. They ignored those who incited the mayhem - such as the Danish imam who traveled to Cairo and stirred up riots over cartoons few Egyptians had seen.

Death threats against Jyllands-Posten continued for years, including a plot by a Pakistani terrorist group that was discovered. Only four U.S. newspapers had the guts to print any of the cartoons to inform their readers. I'm proud to say The Inquirer was one of the four.

The editor at Jyllands-Posten who had assigned the cartoons, Flemming Rose, explained the rationale for running them: "The idea wasn't to provoke gratuitously - and we certainly didn't intend to trigger violent demonstrations," he wrote in the Washington Post in early 2006. "Our goal was simply to push back self-imposed limits on expression that seemed to be closing in tighter."

Rose was referring to a series of decisions at the time by European book editors and museums to avoid photos or exhibits that might offend Islamic fundamentalists, along with the request of a group of Danish imams that the Danish government censor press coverage of Islam.

I spoke by phone to Rose in Copenhagen. (He recently published a prescient book in the United States titled The Tyranny of Silence: How One Cartoon Ignited a Global Debate on the Future of Free Speech.) "Today cannot be a surprise to anyone who has followed events over the past 10 years," he said, sadly.

"Charlie Hebdo was maybe the only paper in Europe that, didn't cave in after what we went through or after the fatwa against Rushdie," Rose continued. Most other media in Europe accepted self-censorship due to intimidation or fear of violence, but "Charlie Hebdo kept making fun of all kinds of religions, including Islam, despite the death threats. Today they paid the price for not being willing to shut up."

The question now, says Rose, is how Europeans and Americans will react to these murders. "Are we going to accept this new order - in which we have to be very careful of what we say? Or are we going to ask ourselves what are the minimum limits in order to live in peace with each other?"

In Rose's mind, those limits should exclude any incitement to violence. "It should be a criminal offense to say 'attack Muslims'." he says, but not to offend Muslims - or any other religious group - in a newspaper or text. That, he says, is the price of living in a democracy, where the right to free speech distinguishes between words and deeds.

Moreover, giving in to self-censorship does no favor to Muslims. Would-be Muslim reformers in the Arab world and elsewhere are suffering from blasphemy laws that threaten death to anyone who criticizes their religion. And the Charlie Hebdo murders are likely to help the European far right and create more prejudice against Islam than any cartoons.

It's long past time to stand up against the assault on free speech in Europe and elsewhere. As Charlie Hebdo's editor, Stephane Charbonnier (killed yesterday), told Le Monde in 2012, "I am not killing anyone with my pen. I am not the violent person here."