Foreign Affairs

Worldwide Indicator Flashing Red As Global Debt Deluge Spooks Investors

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Global bond yields climbed to their highest levels since the 2008 financial crisis Tuesday as rising oil prices, persistent inflation concerns and mounting government debt pushed investors to demand higher returns on government bonds, according to Bloomberg.

The selloff added pressure to governments already facing enormous borrowing needs, while higher rates threatened to increase borrowing costs for American households and businesses. The global bond market was worth roughly $109 trillion, according to the OECD, with governments and companies expected to borrow a record $29 trillion from bond markets in 2026.

The yield on Bloomberg’s gauge of global sovereign bonds rose for a fourth consecutive session Monday, reaching 3.72%, its highest level since mid-2008.

The move accelerated after Federal Reserve Chairman Kevin Warsh reiterated his commitment to bringing inflation under control, while renewed hostilities between the U.S. and Iran sent oil prices higher and raised concerns about further energy-driven inflation.

Warsh warned during his speech at the Federal Reserve Bank of Kansas City’s annual economic symposium in Jackson Hole, Wyoming, on Friday that the Fed would “have work to do” if policymakers were not confident that underlying inflation was returning to the central bank’s 2% target. His remarks helped push up expectations for a September rate hike, according to Reuters.

The 10-year Japanese government bond yield touched 3% for the first time since 1996, while 30-year British government bond yields reached their highest level since 1998. The 10-year U.S. Treasury yield climbed to 4.8%, its highest level since early 2025.

U.S. officials already intervened in foreign-exchange markets to prevent currency instability from spilling into broader financial markets. The U.S. and Japan intervened jointly on July 31 to support the yen after it weakened sharply, while the Treasury Department used its Exchange Stabilization Fund in 2025 to purchase Argentine pesos and established a $20 billion currency-swap framework aimed at stabilizing Argentina’s currency.

Treasury Secretary Scott Bessent defended such interventions as a way to prevent disorderly markets from developing into broader financial crises.

A sustained decline in the dollar could create another problem for the U.S. economy. If the dollar loses value, imported goods and other expenses priced in foreign currencies become more expensive for Americans, reducing purchasing power, while a weaker dollar can also undermine investor confidence in U.S. assets.

That concern is particularly significant as the national debt surpassed $40 trillion; the federal deficit was projected at roughly $1.9 trillion for fiscal year 2026 and some fiscal-policy analysts estimated the country faced upward of $193 trillion in unfunded obligations tied to programs such as Social Security and Medicare.

The 10-year Treasury yield, a key benchmark for mortgages and other consumer and corporate borrowing costs, rose, which could lead to sustained rises in prices for home loans, business financing and other forms of credit. The 30-year Treasury yield reached its highest level since the 2007-2009 financial crisis as investors grew alarmed over the government’s $40 trillion debt.

Bessent responded by announcing a planned buyback of longer-dated Treasurys in which investors interpreted as a move to keep long-term borrowing costs down. Treasury yields have since risen.

Treasury interest costs were already approaching $1.2 trillion annually, according to Reuters.