Recently, I visited Japan and spoke with some of your country’s top leaders in government and in the life sciences sector.

While I was there, I made a case I’ve been making to leaders everywhere I go, in my own country and around the globe: Over the quarter-century that I’ve been leading the Gates Foundation, the world’s largest foundation dedicated to global health, I’ve never experienced a more critical moment for health innovation than the one we are living in right now.

After decades of investment from companies and countries around the world, we are on the cusp of breakthroughs across many of the world’s deadliest diseases — from tuberculosis to malaria to HIV. Yet just as we’re on the cusp of so much potential, many world powers are pulling back.

My own country is making steep cuts to funding for both health research and official development assistance to distribute health innovations to the people who need them the most. And some other donor nations have been following suit.

That creates an important opportunity for Japan to continue to lead the push to innovate the next generation of solutions and distribute them to people around the world. In doing so, Japan can help save lives and spur economic growth both in poor countries and in Japan.

For decades now, Japan has understood the value of global health investment better than almost any other country on the planet. Many nations talk about “universal health coverage” as a domestic priority, not an international one—which is ironic, given that “universal” is right there in the name. But Japan has always understood that in a globalized world, our collective security relies on stopping the spread of diseases everywhere.

In 2000 — the same year that we started the Gates Foundation — Japan used its Group of Eight presidency to get world leaders to focus on the diseases that were causing enormous suffering and wasted potential in low— and middle-income countries and invited African heads of state for the first time ever to a G8 gathering in Kyushu-Okinawa so leaders could start working together on solutions. It’s thanks in no small part to Japan’s leadership that the world came together to build the Global Fund to Fight Aids, Tuberculosis and Malaria — which is among the most effective global health tools the world has.

In the decades since it was formed, the Global Fund has saved a staggering 70 million lives. That’s four and a half times the population of Tokyo.

And as the Global Fund has created greater demand for life-saving preventatives, diagnostics, treatments and cures, Japanese companies have driven extraordinary innovation to meet that demand — from antiretroviral drugs that helped turn HIV from a death sentence to a manageable disease, to the long-lasting mosquito bed nets that have helped keep hundreds of millions of people safe from malaria, to next-generation TB diagnostics that use the power of AI to find cases even in the world’s most remote places. This innovation has created jobs and generated economic growth in Japan while also saving millions of lives in other countries.

Research shows that doubling down on this investment could generate extraordinary returns.

Some of these returns will come to Japan in direct economic benefits, as investing in health R&D directly boosts economic activity and creates jobs domestically. And beyond those direct economic benefits, in a world where diseases easily cross borders, developing and distributing better tools to fight disease makes us all safer. It also better prepares us to take on future pandemics that could cause — as we saw with COVID-19 — tens of trillions of dollars of economic damage and devastation. And when people are healthier, they are also better able to participate in their economies — driving economic growth that, in our globally interconnected economy, benefits us people in Japan as well as abroad.

When we quantify these benefits, the returns are mind-blowing. A recent study estimated that from 1994-2022, global investments in neglected disease research and development amounted to roughly $100 billion — and projected that by 2040, these investments are expected to provide a net economic benefit of nearly $50 trillion. That’s extraordinary. And most important of all, this investment is projected to save a total of over 40 million lives.

Whether you measure them in economic benefits or lives saved and improved around the world, the returns on investing in global health are extraordinary. That’s why the Gates Foundation has spent $100 billion — and plans on giving away $200 billion more — to help take on disease and inequity around the world. But to get back on a path to progress, we will need nations around the world to step up, too.

So today, I hope Japan will continue its extraordinary legacy of health leadership — first, by continuing to invest in the Global Fund as well as Gavi, the Vaccine Alliance, so that they don’t have to narrow their ambitions and turn their backs on people in need of care. That’s an ask I’m making to my own representatives in the United States, to leaders in Europe and to other partners around the world. While I was in Japan, your country announced a commitment of $550 million to Gavi over the next five years — a remarkably generous investment. I hope that Japan will show similarly strong support for the Global Fund as it raises funding for its next five years of work this fall.

Second, I hope Japan will also focus on applying its own innovation engine to develop the next generation of health solutions. The Gates Foundation has partnered with the Japanese government to jointly invest in the Global Health Innovative Technology Fund so that Japanese scientists can develop the next generation of solutions that will save lives around the world — and drive growth for Japan’s economy in the process.

Finally, beyond Japan’s resources and innovation engine, I hope your country will also continue to contribute the visionary moral leadership that you have long displayed. Decades ago, your leadership helped show the world that universal health coverage is not just possible, but essential for creating a truly secure, just and prosperous world. Today, we need your leadership to make sure that we don’t forget it.

Bill Gates is chairman of the Gates Foundation.