Global government bond yields have surged to multi-decade highs as a combination of geopolitical tensions, sustained inflationary pressures, and increased borrowing have unsettled financial markets worldwide. Since late February, conflict in the Middle East has disrupted key oil supply routes, exacerbating energy price volatility and feeding into rising bond yields across major economies including the United States, the United Kingdom, Japan, France, and Germany.

The conflict, involving hostilities between the United States and the Iranian regime, has severely constrained refined oil flows by rendering the Strait of Hormuz hazardous to navigation. Simultaneously, fighting in Yemen, where Iranian-backed Houthi rebels have targeted Saudi vessels and seized strategic ports near the Bab el-Mandeb strait, has further restricted access to vital shipping lanes connecting to the Suez Canal. These disruptions have kept Brent crude oil prices near or above $100 per barrel for much of the year, contributing directly to the volatility in global government bond markets.

This geopolitical shock compounds lingering inflationary effects that have persisted since Russia’s 2022 invasion of Ukraine, which triggered energy price surges and inflation rates unseen in decades. Inflation in the United Kingdom, for instance, reached 11.1 percent—the highest in 40 years. Central banks’ earlier characterizations of inflation as “transitory” proved inaccurate as underlying energy costs remained elevated, prompting monetary authorities in the US, Eurozone, and Japan to raise interest rates. The Bank of England, after resisting premature hikes, is increasingly expected to follow suit at its November 5 meeting amid growing consensus for policy tightening.

Fiscal factors also continue to weigh heavily on bond markets. The substantial increase in government borrowing following the COVID-19 pandemic has led to a surge in bond issuance, driving yields upward as investors demand higher returns. The International Monetary Fund projects that average fiscal deficits among G7 nations will remain elevated at 5.5 percent of GDP into the next decade, largely influenced by expansive U.S. tax cuts and persistent deficits in other member countries. Notably, France’s political deadlock ahead of its presidential election has stalled budget reforms, resulting in a deficit forecast to exceed 6 percent of GDP. Meanwhile, Japan has approved a $135 billion fiscal stimulus package and Germany is advancing a €500 billion investment plan focused on rearmament and infrastructure growth.

The UK has endured particularly sharp increases in bond yields, with the ten-year gilt yield surpassing 5 percent—the highest among G7 countries. This is partly due to the country’s heavy reliance on imported energy, especially gas, whose prices have climbed to four-year highs. Market participants attribute an additional “moron premium” to UK borrowing costs, a legacy of investor mistrust stemming from fiscal policy decisions made during the 2022 mini-budget under former Prime Minister Liz Truss. Structural factors also play a role, as traditional gilt purchasers like pension and insurance funds have stepped back, replaced by hedge funds demanding higher yields. The Bank of England has accelerated its sale of government bonds acquired through quantitative easing, though it announced a recent halt to offloading long-term gilts.

On the corporate side, debt issuance has risen sharply, particularly among artificial intelligence (AI) companies financing substantial infrastructure rollouts. The Bank of England highlighted concerns that this surge—estimated at $450 billion in new debt over the past year—could increase vulnerability to market corrections.

Manufacturing data in the UK reflects the broader economic pressures. Although the S&P Global UK manufacturing purchasing managers’ index indicated growth in September for the 11th consecutive month, the pace of output expansion slowed, hindered by supply chain disruptions, higher fuel costs, and inflationary input pressures. Rising prices for chemicals, electronics, energy, and food, compounded by increased diesel costs, have contributed to input price inflation after four months of declines.

Monetary policy officials at the Bank of England have signaled a willingness to raise rates further to contain inflation risks linked to the Middle East energy shock. Catherine Mann, an external member of the monetary policy committee (MPC), pointed to a “policy uncertainty premium” elevating British bond yields and emphasized the need for a clearly communicated tightening path. Mann, alongside other MPC members who voted for a 0.25 percentage point rate increase to 4 percent at the last meeting, suggested additional hikes are likely. Bank Governor Andrew Bailey acknowledged the increasing difficulty of maintaining current rates in light of oil price pressures, echoing sentiments from committee colleagues Clare Lombardelli and Sarah Breeden.

Looking ahead, the Bank of England faces a fiscal environment with reduced maneuvering space. Chancellor John Healey, preparing for his first budget on October 28, contends with a £10 billion reduction in fiscal headroom amid these complex economic and geopolitical challenges. Meanwhile, UK inflation is forecast to exceed 4 percent in early 2027, substantially above the Bank’s 2 percent target, underscoring the continued impact of energy price shocks and international tensions on the domestic economy.