As troops prepare to set sail for the front, a rising chorus of voices demands an end to criticism of — or even discourse about — the wisdom and propriety of bombing Afghanistan.

Some of the pressure to stifle dissent comes disguised as sympathy for the enlisted men and women who must shoulder the risks and deprivations of going to war. Who can argue with that? Those of us who sit out the action at our keyboards have the easy job.

But this is as true of those who cheer the military solution as those who question it. It is equally true of the politicians and generals who order up military solutions knowing they will never personally find themselves in harm’s way.

The right to dissent from the decisions of one’s rulers lies at the heart of a free society. Defending that core goal — our society’s freedom — is precisely the rationale for undertaking the extreme step of a military assault on another society.

To insist on abandoning our core values as a necessary step in defending them is irrational. To cloak that insistence in the guise of support for our troops is a repulsive bit of intellectual dishonesty.

More of the pressure to silence dissent comes in the form of apocalyptic rhetoric. The battle joined is a “crusade” pitting good against evil, freedom against tyranny, democracy against terror. In such black-and-white struggles, there can be no middle ground.

The scale of the carnage unleashed by the September 11 attacks, and magnitude of the cruelty that conceived it, make it easy to frame the debate this way. Doing so requires overlooking certain inconvenient facts.

Osama bin Laden, the putative incarnation of the evil against which we struggle, is first and foremost a creation of U.S. foreign policy. His network of operatives, like the Taliban movement that harbours him, was financed and supported by the U.S. Central Intelligence Agency — with help from Saudi Arabia — as a means of thwarting Soviet control over Afghanistan. This, on the real-politick theory that the enemy of our enemy is our friend.

Experience apparently hasn’t soured us on the theory. In pursuit of Middle Eastern democracy, we risk repeating that mistake by enlisting such unlikely allies as Pakistan, where General Pervez Musharraf came to power by overthrowing the elected government of President Nawaz Sharif, or Uzbekistan, where 7,000 political dissidents languish in prison, or Saudi Arabia, where beheadings are routine and women suffer oppression similar to that imposed by the Taliban.

The assault on thought in the wake of September 11 takes its most extreme form in the denunciations of anyone who seeks to understand how the United States became a target for such an attack. Anything beyond the official formulation (“They hate freedom and democracy”) is pilloried as the moral equivalent of finding excuses for Hitler’s extermination of the Jews.

“To excuse such an atrocity by blaming U.S. policies,” wrote Salman Rushdie, a writer with firsthand experience of clerical terror, “is to deny the basic idea of all morality: that individuals are responsible for their actions.”

Except that I’ve heard no serious critic of U.S. policy attempt to “excuse” the World Trade Center atrocity, any more than I’ve heard serious historians attempt to “excuse” Nazism by pointing out that the peace treaty ending First World War helped foster Hitler’s rise.

To misconstrue attempts to understand how a megalomaniac like bin Laden finds a pool of embittered partisans from which to recruit his murderous operatives with attempts to excuse him is but another example of intellectual dishonesty.

Which brings us to the widely held misgivings about the military campaign Canada has agreed to join. It’s reasonable to want action against the perpetrators of the September 11 attacks that is effective in the short term without being contrary to our long-term interests. Whether the massive bombing of Afghanistan can pass either test remains doubtful.

U.S. strategists face an unenviable task of finding effective tactics to combat an adversary as elusive and dispersed as bin Laden’s terrorist network. Will smart bombs do the trick? Not according to retired Lieutenant General Ruslan Aushev, a veteran of the failed Soviet campaign in Afghanistan, who likened them to “using a cannon to scatter sparrows.”

“We used aviation, artillery, the newest armaments, and nothing helped,” Aushev said.

The long-term consequences of the bombing campaign are even less propitious. Even before September 11, the United Nations World Food Program estimated that 5-million Afghanis needed food aid. In the panic brought on by the threat of U.S. retaliation, the number rose to 7.5 million. The token food drops that accompanied last week’s bombing don’t begin to address that need.

Like the estimated deaths of 500,000 Iraqi women and children attributed to the U.S.-led sanctions against their country, the bombing may contribute to a human calamity that will nurture future generations of bin Ladens.

Pointing out these pitfalls is not moral relativism, as the shrill proponents of militarism proclaim. It’s basic prudence. Assaults on thought and discourse won’t make inconvenient facts disappear.