Central Banks Are Now Coupling the War to the AI Sell-Off

The path from a missile strike in the Strait of Hormuz to a semiconductor sell-off in Seoul now runs through a central bank. For most of this summer it did not. The U.S.-Iran conflict and the AI spending reckoning moved in opposite directions, each with its own logic and its own victims. On July 8, as the Dow and S&P 500 fell on news that President Trump had ended the Iran ceasefire, Micron Technology rose.

surging demand for memory in the AI era — Micron Technology

Geopolitics pulled one way; AI pulled the other. ^[1] On July 14 the pattern repeated, this time more starkly. Markets rallied on news that June inflation had cooled to 3.5 percent, a relief driven largely by the brief ceasefire that had temporarily reopened oil supplies. On the same day, IBM plunged 25 percent after CEO Arvind Krishna admitted the company had failed to adapt quickly to shifting AI spending. ^[2] Rate-hike relief lifted the broad market; an AI-specific failure cratered one stock. The two narratives did not touch. By July 15 the decoupling was still visible in Europe. The STOXX 600 fell on the resumption of U.S.-Iran hostilities and energy disruptions, including output losses at TotalEnergies. But ASML, the Dutch chip-equipment maker, raised its sales forecast due to AI spending. ^[3] AI was a positive counter-trend inside a geopolitical sell-off. That separation held until a Federal Reserve governor named both forces as the same problem. On July 15, Lisa Cook attributed persistent inflation to two drivers.

If we do not see signs of disinflation soon, I am prepared to act. — Lisa D. Cook

It was the first time a senior central banker had put the Hormuz energy shock and the AI investment boom on the same side of the rate equation. ^[4] The implication was immediate: if both forces were fueling inflation, both would be met by the same rate hikes. And rate hikes compress the present value of the future earnings that AI valuations depend on. The Bank of Korea made that logic operational the next day. On July 16, the BOK raised its benchmark rate to 2.75 percent, its first hike since early 2023. Officials cited rising energy costs linked to the U.S.-Israeli conflict with Iran as the inflation driver. But the hike was made possible by something else: strong economic growth, fueled by a global artificial intelligence boom that pushed chip exports up over 70 percent. ^[5]

Inflation is projected to remain elevated for some time as the impact of the rise in energy prices feeds through with a time lag. — Industrial Bank of Korea

The geopolitical shock forced the hike. The AI boom provided the economic cushion that made it absorbable. And the hike then compressed the same semiconductor valuations already under AI-specific pressure. The full chain, in one decision. Hours later, the KOSPI demonstrated what that chain looks like in a market where all three forces converge. The index fell 6.37 percent on July 16 in what Korean traders called Black Thursday. SK Hynix dropped 11.53 percent and Samsung 8.77 percent on Morgan Stanley reports of data-center delays and Chinese IPO competition: the AI-specific correction. U.S. military strikes on Iran raised energy-supply fears: the geopolitical shock. And the BOK's rate hike compressed the same valuations further: the rate channel. Foreign and institutional investors sold 2.83 trillion won. All three forces hit the same index on the same day. ^[6] The European Central Bank is now caught in the same mechanism. Policymaker Yannis Stournaras said the resumption of U.S.-Iran hostilities had returned the eurozone inflation fight to square one, with investors pricing in two additional rate hikes over the next year. ^[7]

So we’re back to square one and that shows how precarious and volatile is the situation in the Middle East and, as a consequence, it also shows the uncertainty surrounding inflation forecasts and therefore the challenges that policy has to face. — Yannis Stournaras

The Fed, the BOK, and the ECB are now all citing the same geopolitical energy shock as a reason to tighten. Each hike lands on AI valuations already under their own, separate pressure. The Indian rupee shows the coupling in a single asset. The currency hit a record low on July 17, weakened simultaneously by Brent crude's 13 percent surge, a direct consequence of the Hormuz blockade, and by $36 billion in capital outflows to AI and semiconductor sectors in the U.S., Taiwan, and South Korea. India Ratings said the oil surge removed that support and exposed the economy to multiple existing vulnerabilities. ^[8]

However, the recent surge in oil prices removed that support and exposed the economy to multiple existing vulnerabilities. — India Ratings and Research

Geopolitics and AI did not take turns on the rupee. They pulled it down together. But the coupling is partial, not total. Where one force dominates, the old decoupling still holds. Indian equities rallied on July 17 despite the U.S.-Iran escalation. The Sensex gained 964 points and the Nifty rose 1.09 percent, driven by Tech Mahindra's 28.4 percent profit increase and Jio Financial's 155 percent profit jump. Investors, as one report put it, decoupled domestic market performance from the escalating conflict. ^[9] Earnings still matter more than geopolitics in Mumbai. The Nikkei 225 fell 2.96 percent on July 16, but for reasons that had nothing to do with the war. SoftBank dropped 7 percent and Kioxia 12 percent on AI-specific tech losses. Automotive stocks provided a partial offset. The U.S.-Iran conflict, raging on the same day, was not cited as a factor. ^[10] Tokyo's sell-off was a pure tech story. And the Canadian S&P/TSX decline on July 17 carried a headline that named both AI Tech Sell-Off and Geopolitical Tension, but the body of the reporting attributed the downturn largely to growing concerns over artificial intelligence valuations. ^[11] The headline conflated two narratives the substance would not support. The coupling is real enough to shape coverage, but not yet total enough to shape every market. The line between sector-specific rotation and geopolitical contagion has not been erased. It has been bridged. And the bridge is the rate hike, built by central bankers who now name both forces as the same problem. A missile strike in the Strait of Hormuz raises energy costs. Energy costs raise inflation. Inflation raises rates. And higher rates compress the AI valuations that were already falling under the weight of their own excess. The two narratives of the summer of 2026 have not merged. They have been coupled, and the coupling is monetary policy.