In early December 2025, Bank of Japan Governor Kazuo Ueda signaled that the central bank was approaching a moment of reckoning over whether to raise interest rates. The remarks sent tremors through global bond markets. U.S. Treasuries sold off sharply, pushing yields on both 10-year and 30-year bonds markedly higher.
Under normal circumstances, cautious language from a dovish Bank of Japan governor would hardly be enough to unsettle U.S. or global markets. But Japan’s central bank occupies a unique position in the global financial system. It is widely regarded as the “canary in the coal mine.” In February 1999, in a desperate attempt to arrest deflation, the Bank of Japan cut its policy rate to zero—an experiment that later became a template for central banks worldwide confronting deflationary pressure.
Now, that long era may be drawing to a close. A policy shift in Japan would not only reshape its own financial landscape; it could also expose the vulnerabilities of other highly indebted economies, potentially including the United States. The common risk is a sustained rise in government bond yields—and the fiscal stress that inevitably follows.
Japan’s gross government debt stands at roughly 230 percent of GDP, about twice the U.S. level. Net of government assets, the ratio falls to around 130 percent—still high, but not immediately destabilizing. Yet much of those assets, such as land holdings, are illiquid and offer limited practical relief when it comes to servicing public debt.
As long as interest rates remain near zero, debt service costs are manageable. The equation changes dramatically once rates rise. At an interest rate of 4 percent, for example, debt servicing would steadily consume a growing share of the government budget. For years, the Bank of Japan suppressed these pressures through massive bond purchases and yield curve control, targeting specific maturities to anchor borrowing costs. With inflation returning, that implicit fiscal “subsidy” is gradually disappearing.
Japan’s debt dilemma offers no easy exit. Tax revenue already accounts for a larger share of GDP than the OECD average. Rapid population aging makes any attempt to rein in pension or healthcare spending politically and socially fraught. That leaves only one durable option: expanding the denominator of the debt ratio by accelerating economic growth.
Prime Minister Sanae Takaichi’s fiscal stimulus package is designed with that objective in mind. Electricity subsidies, cash transfers to families with children, and even payments to licensed bear hunters are all intended to boost demand and jump-start activity.
Yet demand-side measures are only half the equation. The more difficult challenge lies on the supply side. Higher immigration would help, as would greater labor force participation among women and older workers, comprehensive reskilling programs for aging employees, deregulation in services, and tax incentives to encourage technological upgrading among small and medium-sized enterprises. Japan has taken tentative steps in these areas, but progress remains slow.
As a result, the government’s supplementary budget risks further weakening public finances rather than strengthening them. While outright panic may still be premature, Japan’s bond market has its own early-warning system. Retail investors known collectively as “Mrs. Watanabe” appear to be sensing rising risks.
The implications extend well beyond Japan. There are at least two clear global transmission channels. First, higher Japanese government bond yields would make them more competitive with U.S. Treasuries, exerting upward pressure on U.S. interest rates. Second, the more visible Japan’s debt management challenges become, the more investors are likely to scrutinize other heavily indebted countries.
The United States, however, differs from Japan in one crucial respect. Its tax revenue as a share of GDP remains below the OECD average. Closing even half of that gap would be sufficient to eliminate the primary budget deficit—excluding interest payments—and stabilize the debt ratio.
Politically, though, higher taxes in the United States are as difficult as supply-side reform is in Japan. The Trump administration attempted to address deficits through spending cuts, but the effort largely failed. The result was not “cutting fat” but “cutting muscle.” Reductions in government and university funding for research and public services undermined long-term productivity, while the newly created Department of Government Efficiency delivered little measurable deficit reduction.
Democrats, for their part, are currently preoccupied with a cost-of-living crisis driven by rising food, healthcare, and housing costs. Yet they will also have to contend with higher mortgage rates as interest rates rise—and the possibility of politically toxic inflation after 2028. Electoral success depends on managing both.
Taxing billionaires alone will not close the budget gap or neutralize these risks. What the United States ultimately needs is a broad-based, progressive tax increase, combined with the closure of well-known loopholes such as the preferential treatment of carried interest.
Delivering such reforms would require a fundamentally different Congress and a fundamentally different president. History suggests that political realignments of this magnitude often follow crises—particularly debt crises fueled by surging inflation and interest rates. The open question is whether the United States can achieve that reset without first enduring one.
Commentary
Japan’s dilemma is less a local problem than a preview. For decades, global markets treated ultra-low interest rates as a permanent fixture. That assumption is now unraveling. If Japan—the most extreme case of debt tolerance—can no longer suppress yields without consequence, no advanced economy should assume immunity.
The uncomfortable truth is that both Japan and the United States are running out of painless options. Growth reforms are slow, spending cuts are politically radioactive, and tax increases remain taboo. Markets, however, do not wait for political consensus. They adjust first—and force choices later. The real risk is not that governments act too aggressively, but that they act too late.