A recent article in the New York Times disclosed for the first time an account by the head of the New York City teachers union, Randi Weingarten, of her first meeting with the chancellor of New York City Schools, Joel Klein. I found it fascinating because I too met with Chancellor Klein upon his appointment, in my case as the chairwoman of the New York City Council’s Education Committee.

The contrast between these meetings reflects, at the most profound level, two different views about the need for change in our public school system.

At Ms. Weingarten’s meeting, Mr. Klein asked her about her vision for the pace and strategy of change in the New York City schools. She replied “sustainable and incremental change.” He cringed. No, no, no, he replied, there must be “radical reform.”

When I met with Mr. Klein, I told him “Mr. Klein, you should think of yourself as having been appointed as premier of the former Soviet Union.” He laughed heartily. Mr. Klein agreed with what he thought I meant, which was that he was inheriting a dysfunctional and archaic bureaucracy. True, but what I was really trying to say was that if you are appointed premier of the Soviet Union, you can’t fix the country’s problems by being a better bureaucrat. The problem in New York City public schools wasn’t just the product — it was the system itself. A monopolistic system of education could not achieve the radical change Mr. Klein wanted.

I figured the chancellor would get this ultimately after tussling with the bureaucracy for years but would have this epiphany too late to do anything about it. I was wrong.

Pretty soon, Mr. Klein saw that while he owed it to the children in school to make meaningful improvements now, he owed it to future generations to plant the seeds of radical change tomorrow by advocating educational choice and competition. He became a strong advocate for raising New York’s cap on the number of charter schools and also instituted a policy of placing charter schools in public school buildings.

These policies have had a profound impact on speeding and strengthening charter school growth in New York. He has done this while also making meaningful changes in the traditional public schools by improving the collective bargaining agreements, shifting power and accountability to principals, and introducing new ways to use data and evaluate schools.

Notwithstanding the chancellor’s improvements, the demand for radical change is alive and powerful. Two years ago, I helped open Harlem Success Academy Charter School.

There has been so much demand that we are opening up three new schools in Harlem this fall and we still can’t keep up with demand. We have 3,600 applicants so far for next year. About half of all Harlem age-eligible children applied. That’s about six applicants for each spot. It would have been 30 applicants for each spot if we hadn’t quadrupled our capacity.

There are 20 charter schools in Harlem now. That’s about half as many public schools as there are in Harlem. Every time a charter school opens up, parents immediately snap up the spots.

Most of these applicants are not kindergartners. Rather, they are children in public school. These parents are not disrupting their children’s education because they want an “incrementally” better school. Rather, they are profoundly unhappy with the education their children are receiving. Many are quite conscious of the fact that they were victims of educational malpractice themselves and are desperate for their children to have better schooling.

In Harlem, nearly 75% of eighth graders can’t read at grade level. If a failing school is one in which most of the children can’t read at grade level, then nearly every school in Harlem is a failing school. Ms. Weingarten and the union she represents believe that all we need are “incremental” changes in our public schools. The parents applying to Harlem Success don’t agree. Like Chancellor Klein, they think radical change is in order. They — and he — are right.

Ms. Moskowitz, the former chairwoman of the New York City Council’s Education Committee, is the founder of the Harlem Success Academies.