Japan’s Debt Warning: Rising Borrowing Costs Signal Trouble

Japan’s government debt hit a record 1,324 trillion yen ($9.46 trillion) by March 2025, reaching 234.9% of the country’s economic output.

This is the highest debt-to-GDP ratio among major economies. Most of this debt is owned by Japanese investors, including the Bank of Japan, but that has not stopped market worries.

In July 2025, interest rates on Japanese government bonds jumped. The 10-year bond yield reached 1.58%, up from 1.51% just days earlier.

The 30-year bond yield also climbed, showing that investors want higher returns to lend money to the government for longer periods. These moves happened as the ruling Liberal Democratic Party’s support fell to 24%, its lowest in over a decade.

The party already lost its lower house majority in late 2024, making the political outlook uncertain. Japan’s government spends about a quarter of its budget just to pay interest on its debt.

Every time interest rates rise, that cost goes up. The Ministry of Finance has started to talk about changing how it borrows money, such as selling fewer long-term bonds and more short-term ones.

The government also launched new floating-rate bonds and allowed more investors to buy them. Finance officials say they will keep talking to the market to avoid surprises.

Japan’s debt problem comes from years of slow economic growth, an aging population, and budgets that spend more than they collect in taxes. The Bank of Japan, which owns nearly half of all government bonds, is now buying less, putting more pressure on the market.

With an election coming, the government promises cash handouts, while opposition parties want to cut sales taxes and raise business taxes. Investors worry that either choice could make the debt problem worse.

The recent jump in long-term interest rates shows that markets are losing confidence. This matters beyond Japan. Japanese investors hold large amounts of foreign bonds, including U.S. Treasuries.

If Japanese rates keep rising, some of that money could come home, making it more expensive for other countries to borrow. Japan now faces a crucial test.

If it cannot control its debt and keep borrowing costs low, the effects could ripple through global financial markets. The world is watching to see if Japan can regain market trust and avoid a deeper crisis.