Back in December, when those 34,000 pesky bus and subway workers who belong to Transport Workers Union Local 100 in New York City walked off the job, the news media and local government traffic managers from Riverhead to Richmond Hill did their level best to help minimize the hassle.

Another illegal strike is unlikely this year - although the union and the Metropolitan Transportation Authority are having trouble getting together on an agreement - but if it comes to that, we'll all be given plenty of notice about how our commute will be affected.

I like people doing their jobs. In December, it was the news media keeping us informed with newspaper headlines and top-of-the-hour stories on the radio and the Web as the traffic impresarios struggled to keep the cars dancing on the Long Island Expressway from stepping on each others' toes.

But I've been thinking, too, about the job the union of transit workers has been doing. Not the good work the members of the union as MTA employees do each day, safely moving millions to work and school and home again on the country's largest public transport system. I'm talking about the job of being a union. Although Local 100 has its problems - it rejected the MTA's contract offer in January by only seven votes and remains troubled by factionalism - I see the transit workers carrying out the historic mission of a labor union. Looking closer, I see them acting as a countervailing power in the struggle for economic and social justice - not just to protect the interests of their dues-paying members but to sound the alarm that the general interest of the vast majority of all New Yorkers, and the vast majority of Americans, is at stake.

The health insurance you and I count on to protect our family is at risk as never before. Costs are skyrocketing and working families, businesses and local governments are feeling the pinch. Fewer employers are offering health insurance. About one-third of personal bankruptcy, now at record levels, results from medical bills that can't be paid, even for people with health insurance. And never before have pension plans in the private sector been in such dire shape. Businesses are switching to 401(k) plans to shed costs - and a social responsibility they traditionally shouldered. The result is less security for average workers.

Although the public-sector retirement system in New York remains relatively stable, it will not remain immune from attack by those who want to expand a "you own your own" health and retirement system - a system designed to fatten the coffers of insurance companies, investors and banks.

The struggle of the transit workers is really about the most important domestic issue facing American society: how to maintain jobs that provide a wage to live on and raise a family, and how to provide a decent and secure health insurance and retirement plan. Why would nearly 34,000 workers conduct an illegal strike knowing full well the severe legal and financial penalties that can be imposed on each worker?

There are a number of ways to answer this question. In Harlem, there's a 50 percent unemployment rate among black males. A large number of transit workers are black men, and they know, as most transit workers do, that their union is all that stands between them and sinking to the poverty level. According to the Bureau of Labor Statistics, union members have about a 30 percent wage advantage over nonunion workers. Transit workers generally, whatever their gender or skin color, live paycheck to paycheck. They're not rich, but they know their union job is the best anti-poverty plan.

In America, there seems to be an ethos that any exercise of working-class power is a corruption of the natural order, as if fighting to protect social values such as fairness, equality, safety and security is less important than the dog-eat-dog values of the marketplace. Transit workers have taken significant risks because they do not accept the notion that working people in the wealthiest nation in the history of the world should just surrender to the increasing anxiety we all feel about health care and retirement security.

Their union also plays a strong role fighting for a national health plan for all Americans, consciously connecting their particular fight to preserve what is human and sacred in their lives to the same things we all care about and need: our families, our health, a secure future.

Unlike all too many of us, they join and fight as an independent social force made up of members who are aware, informed, militant and motivated. They're doing their job.

Ever hear of the American dream? Well, it just doesn't fall from the sky. As the old labor song says, "You've got to work for it, fight for it, day and night for it, and every generation's got to win it again."

Gene Carroll is the director of the Union Leadership Program at Cornell University, New York State School of Industrial & Labor Relations, in New York City.