For months, markets desperately tried to believe that inflation in the United States was under control. That illusion is now collapsing. US wholesale inflation surged in April to its fastest pace since 2022, confirming what many central banks were quietly beginning to fear: the Iran war is no longer simply a geopolitical crisis. It is becoming a fully-fledged inflationary shock spreading through the global economy. Producer prices rose 6% year-on-year, well above expectations and the strongest increase in nearly four years. Core producer inflation, excluding food and energy, accelerated to 5.2%, also the highest level in more than three years. This matters enormously because producer inflation is often where the real inflation cycle begins. Consumer prices are what households see. Producer prices are what businesses feel before they pass the pain on to everyone else. And the transmission mechanism is now becoming visible everywhere.

Energy costs surged another 7.8% in April. Transport and warehousing prices exploded by 5%. Trucking costs jumped 8.1%, the sharpest increase since 2009. Processed goods prices recorded their strongest rise in five years. This is no longer confined to petrol stations. The inflation shock is spreading through logistics, manufacturing, distribution and services. Once this process starts feeding into the wider economy, it becomes far harder for central banks to control without damaging growth. The Federal Reserve understands this perfectly well. For months, investors continued hoping for rate cuts despite repeated warnings from Fed officials. Markets wanted to believe inflation would naturally fade once post-pandemic distortions disappeared.

Instead, the global economy has simply moved from one inflationary regime to another. First came pandemic supply chains. Then labour shortages. Then fiscal excess. Now, energy warfare and geopolitical fragmentation. The result is structurally higher inflation volatility. The most dangerous aspect is that real wages are now falling again. American consumers are facing rising food prices, higher rents, more expensive fuel and increasing transport costs precisely when inflation-adjusted income is beginning to decline. That combination is toxic politically and economically. It destroys confidence slowly at first. Then suddenly. The United States is entering a highly uncomfortable phase where inflation remains elevated while economic momentum gradually weakens. Central banks hate this environment because traditional policy tools become far less effective. Cut rates too early, and inflation accelerates further. Keep rates high, and growth deteriorates. The Iran war is therefore creating precisely the kind of stagflationary dynamic markets hoped had disappeared with the 1970s. The problem for the Federal Reserve is that much of this inflation is externally driven. The Fed cannot reopen Hormuz. It cannot lower oil prices. It cannot repair shipping routes. It cannot prevent freight costs from rising if global supply chains are disrupted. Yet it must still deal with the inflationary consequences. This explains why Treasury yields continue moving higher despite growing economic fragility. Bond markets are increasingly accepting that interest rates may remain structurally elevated for longer than investors had previously assumed.

And that creates another major problem for Washington itself. The United States is now financing enormous fiscal deficits at increasingly expensive interest rates. Every sustained rise in yields mechanically increases the federal government’s debt-servicing costs. For years, America benefited from cheap financing conditions supported by global disinflation and strong foreign demand for Treasuries. That environment is disappearing. Persistent inflation combined with rising deficits creates a dangerous feedback loop. Higher inflation keeps yields elevated. Higher yields worsen deficits. Larger deficits require more Treasury issuance. More issuance puts additional upward pressure on yields. Meanwhile, foreign buyers are becoming less reliable. Japan is already experiencing severe stress inside its own sovereign bond market. China continues to reduce its strategic dependence on the dollar system. Oil exporters increasingly diversify reserves. And global investors are becoming more selective about duration risk. The inflation problem is therefore no longer isolated. It is becoming systemic.

The irony is brutal. For years, Western central banks fought deflation as if it were the greatest threat to economic stability. Massive liquidity injections, ultra-low rates and fiscal expansion became permanent policy tools. Now the world is discovering that inflation, once reactivated through geopolitical fragmentation and energy shocks, is far harder to extinguish. Especially when governments remain heavily indebted. Especially when supply chains remain fragile. Especially when wars directly affect energy flows. The latest PPI figures are therefore not simply another inflation data release. They are a warning that the global economy may be entering a new regime in which inflation becomes structurally more unstable, more geopolitically driven, and far less controllable than during the previous decade. The Federal Reserve knows it. Bond markets are starting to understand it. Consumers are already feeling it. And if energy prices remain elevated through the summer, April may eventually look less like an anomaly and more like the beginning of a second inflation wave that central banks are no longer fully capable of containing.