NEW YORK — As they went on their rampage, the men who murdered 12 people in Paris this week yelled that they had “avenged the prophet.” They follow in the path of other terrorists who have bombed newspaper offices, stabbed a filmmaker, and killed writers and translators, all to mete out what they believe is the proper Quranic punishment for blasphemy. But in fact, the Quran prescribes no punishment for blasphemy. Like so many of the most fanatical and violent aspects of Islamic terrorism today, the idea that Islam requires that insults to Muhammad be met with violence is a creation of politicians and clerics to serve a political agenda.

One holy book is deeply concerned with blasphemy: the Bible. In the Old Testament, blasphemy and blasphemers are condemned and prescribed harsh punishment. The best-known passage on this is from Leviticus, Chapter 24, Verse 16: “Anyone who blasphemes the name of the Lord is to be put to death. The entire assembly must stone them. Whether foreigner or native-born, when they blaspheme the Name they are to be put to death.”

By contrast, the word blasphemy appears nowhere in the Quran. (Nor incidentally does the Quran anywhere forbid creating images of Muhammad, though there are commentaries and traditions — “hadith” — that do, to guard against idol-worship.) The Islamic scholar Maulana Wahiduddin Khan has pointed out that “there are more than 200 verses in the Quran, which reveal that the contemporaries of the prophets repeatedly perpetrated the same act, which is now called ‘blasphemy or abuse of the Prophet’ but nowhere does the Quran prescribe the punishment of lashes, or death, or any other physical punishment.” On several occasions, Muhammad treated people who ridiculed him and his teachings with understanding and kindness. “In Islam,” Khan says, “blasphemy is a subject of intellectual discussion rather than a subject of physical punishment.” Somebody forgot to tell the terrorists. But the gruesome and bloody belief the jihadis have adopted is all too common in the Muslim world, even among so-called moderate Muslims — that blasphemy and apostasy are grievous crimes against Islam and should be punished fiercely. Many Muslim-majority countries have laws against blasphemy and apostasy — and in some places they are enforced.

Pakistan is now the poster child for the anti-blasphemy campaign gone wild. As of March 2014, at least 14 people were on death row in that country, and 19 were serving life sentences, according to the U.S. Commission on International Religious Freedom.

The owner of the country’s largest media group has been sentenced to 26 years in prison because one of his channels broadcast a devotional song about the Prophet Muhammad’s daughter while re-enacting a wedding. And Pakistan is not alone. Bangladesh, Malaysia, Egypt, Turkey and Sudan have all used blasphemy laws to jail and harass people. In moderate Indonesia, 120 people have been detained for this reason since 2003. Saudi Arabia forbids the practice of any religion other than its own Wahhabi version of Islam.

The Pakistani case is instructive, because its extreme version of anti-blasphemy law is relatively recent and a product of politics. Mohammad Zia ul-Haq, dictator during the late 1970s and 1980s, wanted to marginalize the democratic and liberal opposition, and embraced Islamic fundamentalists, no matter how extreme. He passed a series of laws Islamizing Pakistan, including an anti-blasphemy law that recommended the death penalty or life imprisonment for insulting the Prophet Muhammad in any way.

When governments try to curry favor with fanatics, eventually the fanatics take the law into their own hands. In Pakistan, jihadis have killed dozens of people whom they accuse of blasphemy, including a brave politician, Salmaan Taseer, who dared to call the blasphemy law a “black law.”

We should fight the Paris terrorists. But we should also fight the source of the problem. It’s not enough for Muslim leaders to condemn people who kill those they consider as blasphemers if their own governments are endorsing the idea of blasphemy at the very same time. The U.S. religious freedom commission and the U.N. Human Rights Committee have both declared that blasphemy laws by definition violate universal human rights (because they violate freedom of speech and expression). They are correct.

In Muslim-majority countries, no one dares to dial back these laws. In Western countries, no one confronts allies on these issues. But blasphemy is not a purely domestic issue, of concern only to those who worry about the internal affairs of countries. It has become the cutting edge between radical Islamists and Western societies — with bloody consequences. It cannot be avoided anymore. Western politicians, Muslim leaders and intellectuals everywhere should point out that blasphemy is something that does not exist in the Quran and should not exist in the modern world.

Fareed Zakaria is a syndicated columnist. His email address is: comments@fareedzakaria.com.