When Congress passed the No Child Left Behind Act in 2003, it was hailed as a major breakthrough toward improving American public education and giving the nation's young people the tools they needed to compete successfully in a global marketplace.

The law's greatest achievement was to focus attention on the ideas that teachers and principals should be held accountable for students' progress; that failing schools ought not be allowed to continue with business as usual; and that achievement gaps between racial or socioeconomic groups are unacceptable.

These ideas represented a revolutionary change in direction for American education policy when they were adopted by Congress at the behest of President George W. Bush, and it can be fairly said that they laid the foundation for all the school reform efforts of the past decade.

But NCLB also had a number of unintended consequences that over time have shown the law to be deeply flawed. Since Congress has been unable to fix it, the Obama administration's only option was the plan the president announced today to offer waivers to states that, like Maryland, are willing to embrace strong school reform efforts.

The authors of NCLB intended to set a high bar for measuring student progress, a laudable goal but one that now appears counterproductive. Specifically, the act required schools to show "adequate yearly progress" on raising standardized test scores, or face some form of restructuring.

At the same time, it called for states to bring progressively larger proportions of their students to proficiency in reading and math each year, and set 2014 as the year by which all students must be fully proficient in those subjects.

In retrospect, it's clear that was an unrealistic goal whose principle effect has been not the rapid increase in student proficiency envisioned by the act but rather a steady rise in the number of schools labeled as failing because they couldn't meet the law's annual targets.

Increasingly, many schools that by any reasonable measure would be judged excellent now face the prospect of failing to meet the law's requirements, including a third of Maryland schools, which are rated No. 1 in national education rankings.

For struggling school districts, the situation is even worse. This year, nearly 90 percent of Baltimore City elementary and middle schools failed to make adequate yearly progress under the law, despite that fact that Baltimore's school reform effort has been one of the most successful in the nation.

Education Secretary Arne Duncan says that within a few years, as many as 80 percent of the nation's 100,000 public schools could be labeled as failing if the law is not changed. But the partisan gridlock in Congress has thwarted efforts to rewrite the legislation.

The waivers being contemplated by Secretary Duncan would allow states to avoid the consequences of having their schools labeled as failing if they embraced the administration's key reform goals, including adopting a "common core" curriculum based on national standards, revising the way teachers and principals are evaluated, and rewarding high-achieving schools that serve low-income students.

Maryland embraced all these initiatives when it applied for and won a $250 million federal grant from the Obama administration's Race To The Top competition last year. That leaves the state well-positioned to qualify for an NCLB waiver later this year.

Fortunately, however, there is no reason to believe that a waiver will be a license for officials in Maryland or elsewhere to slack off on school reform. Despite its criticism of NCLB, the Obama administration has proved itself to be every bit as forceful an advocate for shaking up the status quo in the nation's schools as the Bush administration was. It demonstrated through the Race To The Top program that it would be rigorous in evaluating state reform efforts, and there is every reason to believe it will be just as tough in the waiver process. That means state officials in Maryland and elsewhere will be under just as much pressure as ever to follow the spirit of NCLB, even if they are no longer held to its methods.