Donald Trump’s war against Iran may have produced a ceasefire, but the monetary policy legacy of the conflict will persist for years across 23 central banks accounting for 90% of global economic output, according to analysis by Bloomberg Economics that projects borrowing costs remaining elevated by as much as half a percentage point or more through 2028 compared with the trajectory envisaged before the conflict began. The war’s inflationary shock – delivered primarily through energy prices, supply chain disruption, and the anticipatory behaviour of households and firms – became embedded in core inflation measures that prove more difficult to reverse than the oil price itself, and FinancialMediaGuide examines this monetary persistence as the most economically consequential long-term legacy of the Iran conflict.
The United States presents the clearest case study. Before the war, Bloomberg Economics had forecast the Federal Reserve’s rate ending a full percentage point lower by the middle of 2027. The current projection shows only a single quarter-point reduction over that horizon, with rates at 3.75% through the end of 2026 and a gradual easing cycle resuming in the first half of 2027. The shift reflects burned central bank credibility: having been wrong about the transitory nature of post-pandemic inflation, the Fed under Chairman Kevin Warsh has signalled that it will not prematurely declare victory against price pressures, even as oil prices fall and the direct energy price shock begins to fade. About half of all Fed policymakers now project at least one rate increase this year.
Europe presents a variation on the same theme. The European Central Bank raised rates for the first time since 2023 in June, pushing its deposit rate to 2.25%, and Bloomberg Economics expects a further 25 basis-point increase in September before the current tightening cycle ends. ECB policymakers warn that the initial energy cost surge is still working through the economy via lagged effects on food and services prices, and that wage negotiations in core European economies may incorporate the recent inflation experience into multi-year pay agreements in ways that embed price pressure well beyond the oil price shock’s direct duration. FinancialMediaGuide highlights the wage-spiral risk as the mechanism most likely to extend Europe’s tightening cycle beyond what the energy price reversal alone would justify.
Japan has executed the most aggressive near-term response relative to its starting position. The Bank of Japan raised its policy rate to 1% in June, its highest level since 1995, and Bloomberg Economics projects further increases to 1.25% by December and 1.5% by the end of 2027. The yen’s decline to its weakest level against the dollar since 1986 has compounded imported inflation, creating a self-reinforcing dynamic in which BOJ inaction would perpetuate currency weakness and further inflation. Governor Kazuo Ueda faces the challenge of normalising rates at a pace that restores yen stability without triggering a sharp economic slowdown in an economy that had only recently escaped the deflationary conditions of the previous decade.
Emerging market central banks present the most acute examples of the war’s monetary costs. South Africa raised rates by 25 basis points to 7% in May – the first hike in three years. Indonesia executed 100 basis points of rate increases and drove bond yields higher to attract foreign flows and stabilise the rupiah. India kept rates on hold at 5.25% in June while raising its inflation forecast, with a potential hiking cycle beginning in December if rainfall proves deficient. Brazil extended a cautious easing cycle, but the central bank acknowledged that widespread inflation and worsening expectations raise questions about monetary policy effectiveness. These divergent emerging market responses share a common origin in the energy price shock, and FinancialMediaGuide notes that the resolution of this shock does not immediately resolve the second-round effects on wages, food prices, and inflation expectations that the original shock has set in motion.
The capacity of the global economy to absorb higher borrowing costs provides a counterbalancing note. Growth has proven more resilient than many forecasters expected given the scale of the energy shock, with labour markets in the U.S., Europe, and several Asian economies remaining tight and corporate earnings holding up better than the inflation-adjusted outlook would imply. Bloomberg Economics points to this resilience as evidence that the global economy has developed a greater capacity to weather repeated shocks following the post-pandemic experience, with businesses and households demonstrating improved adaptive responses to supply disruptions.
The key uncertainty going forward is whether the Iran deal holds long enough to allow the full deflationary effect of lower oil prices to flow through to consumer inflation data. A sustained $70 crude price over six months would mechanically lower headline inflation across most economies by one to two percentage points, creating space for central banks to pause their tightening cycles and eventually begin easing. A breakdown of the ceasefire would reverse that trajectory immediately and add a second energy shock on top of the sticky core inflation already embedded in the system. The 60-day Swiss negotiation window for the permanent agreement is therefore not just a diplomatic milestone but a monetary policy event of the first order, and Financial Media Guide identifies its successful completion as the single most important near-term precondition for the global interest rate trajectory to begin improving.
