EVERYBODY IS IN FAVOR of his own free speech. It’s the other guy’s that is always the problem.

Thus, people who feel strongly about a political philosophy might seek to silence those who disagree on the grounds that their speech is offensive, hateful and destructive of the public good. When the force of the state is employed to shut up the dissenters and troublemakers, the citizens’ God-given right to free speech — the very essence of liberty — ceases to be respected. Speech becomes a privilege reserved to the powerful.

There are very strong forces around the world right now trying to strangle debate on public issues.

As everybody knows, Danish journalists and other citizens have come under attack because, three years ago, a news-paper there dared to publish cartoons questioning terrorists’ appropriation of the Muslim religion to justify their brutality.

In France, a court this spring found former film star Brigitte Bardot guilty of inciting racial hatred and fined her 15,000 euros (about $23,000) because she had protested the slaughter of animals for the Muslim festival of Eid al-Adha and pleaded that the animals be stunned before being killed. Her criminal statement, made in the context of the festival, was that Muslim immigrants were “destroying our country by imposing their ways.”

Unfortunately, intolerance of ideas is now creeping much closer to home.

In Canada, the highly entertaining and thought-provoking writer Mark Steyn has been put on trial for thought crimes in a number of kangaroo courts called “human-rights commissions.” At this writing, two of the courts have dismissed charges against him. But the process itself, entailing enormous hassle and legal bills, is designed to chill free speech.

Maclean’s magazine in 2006 ran an excerpt of Mr. Steyn’s best-seller America Alone, leading the Canadian Islamic Congress to complain to the government that the magazine was “flagrantly Islamophobic” and “subjects Canadian Muslims to hatred and contempt.” In his book, Mr. Steyn explored the birthrates of Muslims and non-Muslims in Europe and argued that Muslims would eventually be in a position to impose their cultural values on the continent (hence the title).

He also got into trouble for quoting an imam in Norway who observed that “the number of Muslims is expanding like mosquitoes.” The accuracy of a quote, as the tribunal saw it, was no reason to throw out the complaint before subjecting the accused to enormous legal bills.

As a battered and wearied Maclean’s noted after the latest dismissal: “We continue to have grave concerns about a system of complaint and adjudication that allows a media outlet to be pursued in multiple jurisdictions on the same complaint, brought by the same complainants, subjecting it to costs of hundreds of thousands of dollars, to say nothing of the inconvenience.”

Such a system of government adjudication of thought crimes inevitably stifles debate.

Lest we Americans grow smug about our cherished rights, politicians are at work here, too, to exploit the power of the government to silence the people.

At a recent Washington breakfast, House Speaker Nancy Pelosi revealed that she and her fellow House Democrats want to re-impose the “Fairness Doctrine” — a measure that would essentially wipe out political talk radio, which tends to leans to the right. That would rid the Democrats — who enjoy supportive treatment in much media coverage, as well as in college classrooms, where students often receive indoctrination of their views — of a powerful voice of dissent.

The Fairness Doctrine, first imposed in 1949, subjected broadcasters to heavy fines if they carried political commentary that in the government’s view lacked “balance.” That, of course, chilled speech. Broadcasters simply canned the politics rather than risk the fines. When the doctrine was removed in 1980, talk radio boomed, as ideas could finally be discussed freely on the air. For one reason or another, conservative shows tended to draw better ratings than left-leaning ones — which is why the Democrats, shamefully putting political power ahead of values of freedom, want to shut them down.

Such anti-American techniques are bipartisan, of course. John McCain, the presumptive GOP nominee for president, was the co-author of a campaign-finance “reform” that made it harder for citizens and candidates to challenge incumbents. The U.S. Supreme Court last month struck down part of the legislation as unconstitutional.

The lesson in all this is that freedoms we think are ours can always be threatened and whittled away. We must remain vigilant. Politicians in general care more about maintaining and enhancing power than defending anyone’s rights. They will gladly serve special interests at the expense of the constitutional liberties they solemnly swear to uphold.

It is easy to defend popular speech, or that with which we agree. The real test of our devotion to liberty is whether we defend the right to speech we find wrongheaded or discomfiting. As the Founders well understood when they appended the First Amendment to the Constitution: Once free speech goes, government and the special interests it serves can have a field day denying us our other rights and protections.

Edward Achorn is The Journal’s deputy editorial-pages editor ( eachorn@projo.com).