Global bond markets tumble as Middle East tensions stoke inflation fears

United States and Iran exchanged strikes for the first time since July, sending oil prices up more than two per cent and reigniting worries that tighter monetary policy could curb growth. The fallout sparked a coordinated sell‑off in sovereign bonds, with the 30‑year UK gilt reaching its highest level since 1998 and the 10‑year yield climbing to a post‑crisis peak not seen since the 2007‑08 financial turmoil.

Investors are now grappling with a dual threat: stubborn inflation that could force central banks to keep rates higher for longer, and geopolitical risk that may tighten energy supplies. Both factors weigh on equity valuations and raise the cost of borrowing for governments and corporations alike.

Yield spikes across major economies

In London, the 30‑year UK government bond yielded just under 5.3 per cent, the strongest since 1998, while the 10‑year gilt rose to a level last seen during the global financial crisis. Across the Channel, Eurozone inflation hit 3.3 per cent in August, a three‑year high, fuelling expectations that the European Central Bank will raise rates at its upcoming meeting.

In Tokyo, the 10‑year Japanese bond yield touched the 30‑year benchmark of three per cent, reflecting concerns over the government’s expansive fiscal plans. Meanwhile, the US Treasury 30‑year yield hovered just below 5.3 per cent, echoing levels from 2007, and the 10‑year yield reached its highest point since January 2025.

"The bond sell‑off has... been a global affair," said Jim Reid. He added that the "main culprit was the weekend escalation in the Middle East that saw the US and Iran exchange strikes for the first time since late July".

Markets react to oil and geopolitical risk

Oil prices jumped over two per cent after Donald Trump warned of further action against Iran, including targeting the key export hub of Kharg Island. The surge added pressure to equity markets: the Dow Jones fell 0.4 per cent, the S&P 500 slipped 0.4 per cent and the Nasdaq dropped 0.7 per cent. European indices mirrored the trend, with the FTSE 100, CAC 40 and DAX all in the red.

In Asia, the Tokyo Nikkei and Hong Kong’s Hang Seng also fell, while the Chinese Shanghai Composite slipped modestly. The yen weakened against the dollar despite comments from Scott Bessent that Japan would support its currency, hinting that the Bank of Japan may tighten policy at its next meeting.

Looking ahead

All eyes now turn to the Federal Reserve meeting on 16 September. Upcoming US jobs and consumer‑price data will shape expectations on whether the Fed will lift rates further. Kevin Warsh’s recent hawkish remarks have already nudged market bets toward a hike.

Meanwhile, the fast‑fashion giant Shein saw its Hong Kong debut tumble 10 per cent before clawing back to near‑flat, underscoring the broader market nervousness. For European investors, rising energy costs are also feeding inflation, as noted in a recent report on German inflation trends.

With bond yields at multi‑year highs and oil markets volatile, the coming weeks will test whether central banks can steer economies through the twin challenges of price stability and geopolitical uncertainty.