Jeffrey Sachs is director of the Earth Institute at Columbia University.

In the fight against extreme poverty, we face a puzzle. When the U.N.’s Millennium Development Goals were set in 2000, they included both health and education objectives. The health goals were pursued with vigor — and money — and great progress was achieved. Yet the pursuit of basic education languished. The U.S. government and others dropped the ball on an agenda that should have been a no-brainer.

When the goals were set, I worked closely with U.N. Secretary General Kofi Annan to help launch the Global Fund to Fight AIDS, Tuberculosis and Malaria. Despite the knee-jerk opposition of some cynics, the Global Fund received billions of dollars, as did new U.S. programs such as the President’s Emergency Plan for AIDS Relief (PEPFAR) and the President’s Malaria Initiative. Nearly 15 years later, we know that these programs have performed strongly. The aid worked as hoped, and the diseases are coming under control.

Yet creating a similar global fund on education proved impossible. The cause of universal access to education turned out to be a policy orphan, unable to mobilize the same kind of donor interest as disease control did. Yes, modest aid helped millions of children attend primary schools, but because of the shortfalls, those schools often lacked basic materials, trained teachers and even safe water. Millions of other kids remain out of school.

Why the difference? I’ve scratched my head over this for 10 years. Perhaps the life-and-death stakes of health crises are more dramatic. Perhaps it was because the pharmaceutical industry helped to scale up the health response while the private sector was strangely absent on global education. Perhaps world leaders simply failed to put in the needed effort.

But there is something absurd, and deeply troubling, about tens of millions of impoverished children being out of school, often in conflict zones, because of a lack of financing so modest it should make us blush. When we fail to educate a poor child today, we may well meet that child again later as a member of Boko Haram or al-Qaeda, at a cost of billions of dollars.

On Thursday, we can begin to change this. Governments and organizations will gather in Brussels to renew their financial commitments to primary education for the world’s poorest children. The Global Partnership for Education is the main world advocacy group for children who won’t learn to read, write and count unless the world steps forward to help. In its current replenishment round, the GPE is asking for $3.5 billion over four years, or roughly $1 per year from each citizen of the developed world. It’s hard to imagine a better investment.

This issue should be a slam dunk, but it’s not. As of today, there is no guarantee the United States will answer the call for a contribution of just $250 million over two years. Do we really need to beg Washington for $125 million a year, an amount equal to around two hours of Pentagon spending?

As with public health, education donations are easy to track from source to use: supplies; teacher training and deployment; and infrastructure such as classrooms, running water and sanitation. The GPE asks recipient countries to make plans and set quantitative goals and milestones. It’s not rocket science, just good and decent management on behalf of children.

But this replenishment round should aim higher than that. What’s needed is a global effort for education that truly befits the 21st century. Right now, we are fighting to provide primary education for around 60 million kids. But we should also be aiming to ensure access to secondary education for the hundreds of millions without it.

Indeed, our efforts should go especially toward educating girls, to ensure they have every chance to complete a secondary education and gain skills that will allow them to enter the labor force rather than being forced into marriage as teenagers. Educating girls transforms communities, and the benefits are passed to the next generation, from mother to children.

My colleagues and I have been pursuing such a course with the telecommunications leader Ericsson in a project called Connect to Learn. The aim is to use information technology to help enable girls in poor villages in Africa to complete high school. Connect to Learn classrooms are equipped with online educational materials that can provide a world of information in schools that have few, if any, books. Just as rural communities have leapfrogged banking by making payments on mobile phones, so, too, these communities could use technology to leapfrog ahead in education.

Of course, we need to scale up Connect to Learn and related initiatives by orders of magnitude, to reach hundreds of millions of kids, not just hundreds or a few thousand. For that, we need the partnership of big telecom companies, social networking giants, national governments, private donors and many others, all pooling their resources into a flexible and creative Global Fund for Education. This is the goal to pursue in Brussels this week.