Updated: 3:12 p.m.

Unless Congress blows it, the United States has the best chance ever to finally make its public education system world class.

There’s widespread awareness — not just among education reformers, but employers and ordinary people — that American schools are second-rate by international standards and that it’s dangerous to the nation’s economic health and national security.

President Ronald Reagan’s administration first warned in 1983 that we were “A Nation at Risk” — that, unless reformed, U.S. education would undermine America’s competitive position in the world.

The message is finally getting through, and there are encouraging signs of positive action. The danger is that Congress will stifle the progress just as it’s achieving liftoff.

Specifically, an unholy alliance — likely, an undeclared one — could develop between Tea Party Republicans bent on slashing education funding and dismantling the U.S. Department of Education, and Democrats influenced by teachers unions who want to dilute federal accountability standards.

Republicans’ budgets for this fiscal year propose damaging cuts in school improvement funding and college student aid — and eliminating the AmeriCorps program, which supplies poverty schools with volunteer tutors.

What’s more, it’s not clear that Congress will pass a rewrite of President George W. Bush’s reformist No Child Left Behind law this year, designed to improve its testing, accountability and school-turnaround policies.

All this would undercut significant forward movement on reform — both awareness of the need and actual progress toward improvement. Surveys of employers show they can’t find workers with the skills they need. An Education Next poll last year showed that only 18 percent of Americans would give U.S. public schools an A or B grade.

Test results show they have it right. Only 30 percent of high school graduates are proficient in math and reading. The latest Organization for Economic Cooperation and Development International Assessment report ranked the United States 14th out of 34 developed countries in reading skills and 17th in science.

The America’s Promise Alliance, founded by Gen. Colin Powell, attracted massive publicity with its alert two years ago that a third of all high school students — and 50 percent of minority students — don’t graduate on time, with 7,000 a day dropping out.

Last year, the movie “Waiting for Superman” graphically exposed the schools’ systematic failure. It didn’t win an Oscar (it should have), but Oprah Winfrey took notice and millions saw it.

The nation’s governors, on a bipartisan basis, have decided to adopt common standards for measuring graduation rates — and, even more important, to adopt a common core curriculum for what kids learn based on international standards.

And President Barack Obama, in the pattern of Richard Nixon going to China, has taken on the most persistent lobby opposing reform — the teachers unions — and has made the case that the schools should serve the interests of their students, not the adults who oversee them.

With $4 billion in incentive funding — the “Race to the Top” program — the administration persuaded dozens of states to adopt reforms such as lifting limits on charter schools and basing school and teacher evaluations on students’ progress. 

The administration and other reformers also are pushing for longer school days and years as well as greater use of new technology, to move U.S. education out of the 19th century and into the 21st.

Under pressure, the unions have begun paying lip service to reform, have signed on to some “Race to the Top” state-level reforms and have even negotiated a few local contracts allowing for teachers to be rewarded — even fired — based on student achievement.

A year ago, Obama, Education Secretary Arne Duncan, Powell and his wife, Alma, now chairwoman of America’s Promise, launched a “Grad Nation” campaign aimed at raising the U.S. graduation rate to 90 percent by 2020.

This week in Washington, more than 1,000 local and state leaders and representatives of nonprofits, corporations and foundations gathered to review Grad Nation’s progress on the dropout issue and launch a “civic Marshall Plan” designed to help students at the nation’s lowest-performing schools.

(Disclosure: My wife is president and CEO of America’s Promise.)

The Marshall Plan calls for local communities to mobilize around reforming more than 1,746 “dropout factory” high schools — those graduating fewer than 60 percent of their students — and providing their students with tutoring, after-school activities, and help with health and family problems.

At the conference, a co-sponsor, the Alliance for Excellent Education, unveiled a study showing that if the dropout rate for the 2010 graduating class were half of what it is now, 650,000 high school graduates would collectively earn $7.6 billion a year more than they do as dropouts, stimulate $9.6 billion in economic activity, increase state tax revenues by $713 million and generate 54,000 jobs.

It’s a powerful argument for investment in education and reform, yet House Republicans are bent on cutting school improvement grants from $546 million to $200 million.

They’d also eliminate federal literacy programs and cut Pell Grants for college students by 24 percent — at a time when half of new jobs require post-secondary training and the U.S. has fallen from first to ninth in the world in college completion.

Republicans are inclined to support — as they should — resurrection of the Opportunity Scholarship Program for the District of Columbia, canceled by Democrats because it included vouchers for poor children to attend private schools as well as aid to charters and the D.C. public schools.

But the GOP ought not to be cutting any aid that will upgrade American education.

There’s no question that the government is deep in debt, but part of the way to get out — as Obama rightly says — is to “out-educate” the rest of the world, as America once did.

A popular movement is under way to do so again. Congress would not be doing the country a service by stifling it.