Last fall, a European colleague asked me why Americans didn’t take to the barricades over economic injustice.

I tried to explain that we didn’t do things like that, the United States wasn’t France, and Americans could make their protest felt at the polls. That was then. These days, as public anger soars over AIG bonuses, fanned by cable television and Congress and indulged by President Obama, it seems we have arrived at a Gallic moment — or something more scary.

When an Iowa Republican, Sen. Charles E. Grassley, actually suggests that AIG executives follow “the Japanese example,” come before the American people, bow, and “commit suicide,” you know we’re reaching hysteria levels.

Scared politicians are throwing out short-term fixes to placate the public, instead of harnessing the anger to support long-term economic changes. AIG rage threatens to worsen the financial crisis at home and around the world.

Don’t get me wrong. I understand the public’s wrath. I’m angry, too. My employer has filed for bankruptcy and my 401(k) has withered. I have visions of Bernie Madoff in the stocks confronted by his elderly victims with rotten tomatoes in their hands.

But the emotions generated by AIG bonuses are so intense they clearly reflect something much deeper. This affair has freed Americans to air long-held economic grievances they have held in check for a decade.

Middle-class frustrations over years of stagnant wages and rising income inequality have finally exploded. Already, figures from 2005 showed that the top 1 percent of Americans received 21.8 percent of all reported income (the largest share in 80 years), and the top 10 percent collected half.

Long-standing unease at CEO compensation — which has soared to obscene heights — is also going public. Those frustrations were tempered in recent years by increases in home values, and a rise in credit card debt. But, now that the debt bubble has burst, middle-class Americans realize they may be permanently poorer.

So it’s not surprising that we see demonstrations in front of AIG offices, and the demonization of all of its staff — regardless of whether a given person deserves this. The New York Times reports that AIG executives have hired security guards to protect themselves in their houses. The company has become a symbol of America’s economic frustrations and worries.

Many Americans feel they have been cheated by Wall Street and corrupt politicians. Indeed, Obama was swept into office as a result of such feelings.

Demonstrators in Dublin, Eastern Europe, Greece, China, Russia, and of course Paris have already taken to the streets over the global recession. So why not in America?

Yet AIG rage can become a dangerous phenomenon if it is misdirected or misused.

So it is depressing to watch how anger over AIG is being whipped up by the talk shows and cable television. Lost in the cacophony are the details — which are hard to understand anyway — of exactly who did what. (The mainstream media are at least trying to sort this out, with varying success.)

The din virtually blots out the bigger picture: how the rescue of AIG relates to the urgent need to save the banking system and reinvigorate bank lending. Meantime, AIG rage has inspired demagoguery among scared politicians trying to deflect blame. This in turn has produced quick fixes that may undercut long-term economic reforms.

AIG rage, for example, led the House last week to vote for the levying of a 90 percent tax on bonuses paid by all firms receiving government aid. Yes, there needs to be a change in the bonus system, which rewards irresponsible risk-taking. But a blanket punitive tax may drive away talent needed to revive those firms. It may also scare away private investors needed to join government in buying up toxic assets from banks.

And once we start using taxes as a bludgeon, there’s no telling who may be the next victim. Think Richard Nixon trying to “screw” his enemies with IRS tax audits. Or Russia’s Vladimir Putin, who uses confiscatory taxes to destroy companies headed by rivals.

AIG rage may also fuel a congressional push for more protectionist trade measures, which could fuel a global trade war. An Obama ban on a few Mexican long-haul trucks entering the United States has triggered

$2.4 billion in Mexican tariffs on American items.

“Leaders must not heed the siren song of protectionist fixes, whether for trade, stimulus packages, or bailouts,” World Bank President Robert B. Zoellick said recently. “Economic isolationism can lead to a negative spiral of events such as those we saw in the 1930s, which made a bad situation much, much worse.” That is a road down which the United States must not travel.

Can Obama resist AIG hysteria? His calm demeanor has cracked over the scandal; he has denounced the bonuses and promised to recoup them. But the president cannot afford to get distracted by populist rage, or by those who would exploit it. The only hope for addressing the fairness deficit in America’s economic life is for him to keep his focus on the big stuff.

Yet the AIG tale offers grim warning of how easy it will be to stir public anger in a country whose middle class didn’t used to think of marching to the barricades. Obama beware.