Global debt reached a record $365 trillion in the first half of 2026, according to data from the Institute for International Finance (IIF), representing 311 percent of the world’s gross domestic product (GDP). This figure underscores concerns about the sustainability of debt levels in major economies, particularly among high-income countries.

The IIF highlights that mature market governments now spend more on interest payments than the world invests annually in artificial intelligence (AI), defense, or energy sectors. The institute warns that debt has evolved into a significant political issue, contributing to a cycle of short-term policy measures centered around elections, which exacerbates long-term fiscal vulnerabilities. Notably, the IIF’s analysis points to greater risks in high-income economies compared to emerging or developing countries.

While the global debt-to-GDP ratio rose less than 10 percentage points between 2018 and mid-2026, the trajectory has been volatile. Following a peak of 337 percent in early 2021, driven largely by pandemic-related borrowing, the ratio declined by 27 percentage points by the end of 2023. This reduction is largely attributed to inflation, which, by eroding the real value of debt, has historically served as an informal debt-reduction mechanism for countries capable of issuing debt in their own currency.

However, inflation’s impact has also led to persistently higher interest rates than those before the COVID-19 pandemic. In mature economies, government interest expenses surged by 1.5 percentage points of GDP from December 2021 to August 2026, reaching an average of 3.3 percent of GDP. In the United States, interest costs grew by 1.6 percentage points over the same period.

The increase in interest rates adds pressure on government borrowing costs, but the evolving landscape of corporate debt issuance is also noteworthy. AI-linked corporate bonds have seen a dramatic rise, with expected issuance reaching $541 billion in 2026, up from $90 billion in 2023. These bonds tend to feature longer maturities—averaging 13.4 years this year compared to 2.5 years for U.S. Treasury securities—and only marginally higher interest rates than government debt. This contrast reflects a sharp shift toward short-term government borrowing in the U.S. and other advanced economies.

The IIF expresses relatively less concern about private sector debt and the borrowing practices of emerging markets. Private credit remains a minor component, accounting for around 5 percent of outstanding non-financial corporate debt globally. Sovereign Eurobond issuance in 2026 is occurring at a record pace amid improved country fundamentals, and lending aligned with environmental, social, and governance (ESG) criteria has reached $1 trillion year-to-date.

Despite the recent decline in global debt ratios, the IIF cautions that the current picture is “deceptively benign.” Structural changes, including sustained higher interest rates and political reluctance to impose fiscal austerity, suggest that public debt accumulation in high-income countries may continue unabated. The shift toward shorter maturities in government debt increases vulnerability to sudden spikes in borrowing costs, potentially triggered by currency depreciation or other shocks.

Political uncertainties add additional risk. Potential triggers include geopolitical conflicts, energy supply disruptions, intensifying trade disputes, and domestic political fragmentation, particularly in the United States and the European Union. The report notes that a rise in far-right political influence could strain intra-EU support frameworks.

Economic commentators referenced in the report conclude that while a sudden debt crisis is not imminent, the growing constraints on fiscal flexibility pose significant challenges. As the late economist Herbert Stein cautioned, unsustainable trends must eventually halt, though the timing is uncertain. Another economist, Rüdiger Dornbusch, emphasized that financial crises often arrive unpredictably and escalate rapidly, a dynamic that remains relevant today, especially considering parallels between emerging markets’ past crises and vulnerabilities in advanced economies.

For countries able to borrow in their own currency, options such as financial repression and inflation remain tools to manage debt burdens, although such measures carry risks and limitations. The ongoing debate over monetary policy settings, including calls for lower interest rates from some political figures, reflects these tensions in managing long-term debt sustainability amid evolving economic conditions.