US national debt crossed $40 trillion in 2026, and annual interest payments surpassed $1 trillion for the first time. The yield on 30-year US Treasury bonds reached 5.33% on August 18, 2026 — the highest level since 2007. The rise in long-term yields reflects a combination of persistent fiscal deficits and heavy bond issuance, as governments continue to roll over maturing debt at materially higher interest rates than those locked in during the low-rate era of the 2010s and early 2020s.

The UK finds itself in a similarly uncomfortable position. Gilt yields approached 6%, a level not seen since 1998, and net debt interest for the 2026/27 fiscal year is estimated at £109 billion. For context, that figure now rivals major spending categories in the UK budget, intensifying pressure on future fiscal decisions.

Elsewhere in Europe, France faces projected debt-servicing costs of around €59 billion in 2026, while Italy is on a trajectory where interest payments could consume roughly 9% of government revenue by 2028. Japan's long-term yields are approaching 30-year highs as global borrowing-cost pressures bleed across borders. The tightening is notable in Japan's case because the country has spent decades anchored near-zero rates, with the Bank of Japan historically absorbing large portions of government debt issuance.

Across the G7 as a whole, interest payments have exceeded defense spending in most member nations since 2024 — a comparison that has gained political salience as several governments simultaneously raise defense budgets.

Developed-market general government debt is projected to rise by $4.2 trillion to reach $75.8 trillion by the end of 2026, equivalent to roughly 104% of GDP. Most G7 nations now sit at or above the 100% debt-to-GDP threshold. Germany remains the notable exception, having maintained stricter constitutional limits on deficit spending through its debt brake.

For investors, rising yields on sovereign debt create a genuine alternative to equities for the first time in over a decade. A 5.33% yield on a 30-year US Treasury is a real return that risk-averse institutions — pension funds, insurers, and endowments — will find increasingly attractive. Higher sovereign yields also feed through into corporate and mortgage borrowing costs, transmitting the fiscal pressure into the broader economy.

Italy's trajectory toward interest consuming 9% of government revenue by 2028 is particularly worth watching. As the eurozone's third-largest economy, Italy's debt dynamics have periodically tested the resilience of the single currency project, most acutely during the eurozone debt crisis of the early 2010s. Whether the European Central Bank's bond-market backstops and Italy's domestic primary surpluses continue to contain spreads will be a key marker of how the wider debt-cost squeeze resolves.