Escalating crude prices have pushed the already fragile global bond market to a critical juncture. Following the renewed US-Iran conflict, Brent crude surged 4.5% within two days and is up 51% year-to-date. This spike has driven 10-year government bond yields in Germany, the UK, and Japan to their highest levels since 2011, 2008, and 1996 respectively on Tuesday, while US 10-year Treasury yields also climbed to levels rarely seen since the financial crisis.

Amid the market turmoil, US Treasury Secretary Bessent publicly stated at the G20 summit that high yields reflect economic strength, vowing "we will get through this" — but investors remain unconvinced. The core risk lies in the fact that years of fiscal stimulus and military spending have significantly eroded the fiscal foundations of major industrialized nations, while rising oil prices are spreading inflationary pressure from energy into broader consumer prices. According to the Wall Street Journal, 54% of goods in the Fed's preferred inflation basket have seen year-over-year price increases exceeding 3%, well above the historical average of roughly 32%.

The question investors face now is whether the bond market can absorb the pressure without spilling into equities if the September 11 CPI data comes in hot or if the Fed fails to deliver on rate hikes at its subsequent meeting.

Where the Selling Started

The immediate catalyst for the synchronized global bond selloff is the renewed military conflict between the US and Iran. Brent crude jumped 4.5% in two trading sessions, bringing its year-to-date gain to a staggering 51%. The sharp rise in energy prices is intensifying inflationary pressures across regions. Eurozone inflation accelerated to 3.3% in August from July's 2.9%, exceeding expectations. Analysts point out that the global synchronization of this bond selloff indicates the driving force is the oil price — a global factor — rather than any single country's fiscal problems.

Following the COVID pandemic and the Russia-Ukraine war, years of fiscal stimulus and military expenditures have dramatically worsened the fiscal positions of major industrialized countries. The accumulated deficits act like dry tinder, and the rekindling of conflict with Iran is the spark that ignited it.

Bessent's Defense and the Fiscal Timeline

Confronting market pressures, Bessent defended the current situation at a G20 press conference in Asheville, North Carolina. He attributed elevated yields to three factors: robust economic growth, a "transitory inflation shock" from rising energy prices, and a surge in capital expenditure driven by the artificial intelligence investment boom. Bessent described AI-related capital spending as creating a short-term "dilemma" for the bond market, but argued that over the long term, these investments would deliver significant productivity gains, ultimately producing a "strongly disinflationary effect" that would push both inflation and long-term yields lower.

On fiscal consolidation, Bessent stated Monday that a comprehensive package might still take weeks or even months to materialize, dashing market expectations for swift government action to reduce deficits. He also expressed confidence that oil prices would eventually retreat, though "we don't know if it's today, tomorrow, or next week."

The Fed's Stance and CPI as Pivotal Factors

With fiscal policy unlikely to provide near-term relief, market attention has turned to monetary policy. Fed Chair Warsh, speaking at the Jackson Hole symposium last week, highlighted signs of broadening inflation — 54% of goods in the Fed's preferred inflation metric are rising more than 3% year-over-year, versus a historical average of about 32%, showing that energy price increases are seeping into wider inflationary pressures. Warsh indicated the Fed is prepared to act to curb inflation.

However, Bessent told CNBC that central banks traditionally do not raise rates in response to supply shocks unless there are "second or third order effects." This statement creates a subtle tension with Warsh's hawkish signals. The market now faces two crucial junctures: the September 11 CPI release, and the Fed's policy meeting five days later. If inflation data exceeds expectations, or if the Fed fails to deliver on its promised rate hikes, analysts warn that the risk of another market downturn in September rises significantly.

Are Stocks Next in Line?

During the G20 summit, Bessent was simultaneously managing multiple fronts: managing the yen-dollar exchange rate, stabilizing long-term Treasury yields, and addressing renewed trade friction with Canada. According to Japan's NHK, Bessent told the Bank of Japan governor and finance minister that "Japan needs to make clear to markets that it is moving toward higher interest rates and fiscal sustainability."

Analysts note that until stability returns to the Persian Gulf region, central bank tightening and fiscal consolidation efforts may only have marginal effects. With oil prices remaining elevated and inflation expectations rising, the pressure on global bond markets is unlikely to reverse in the near term — and once that pressure spreads further, equities could be the next asset class to feel the strain.