At 6. 35 on a Tuesday morning, four oil tankers turned back from the Strait of Hormuz rather than risk the passage — and within hours, that decision was being priced into markets around the world. Brent crude rose $2. 49 to $76.

65 a barrel, a gain of 3. 4%, after the United States carried out a new wave of military strikes against Iran and revoked the licence that had allowed Tehran to sell oil internationally. The moves placed fresh strain on a ceasefire that had been agreed only weeks earlier, with negotiations over a permanent settlement still incomplete. The strait, through which a significant share of the world's seaborne oil supply passes, became the focal point of the crisis after at least three tankers were struck by projectiles.

Ship-tracking data confirmed the four vessels that turned back, though at least two crude tankers did complete the transit, each carrying approximately two million barrels of oil. NATO Secretary General Mark Rutte, speaking to journalists ahead of a summit of alliance leaders in Ankara, described the US strikes as "absolutely necessary. " Asian equity markets absorbed much of the turbulence. Tokyo's Nikkei fell 1.

6%, while Seoul's Kospi index tumbled nearly 5% — a striking reversal for a benchmark that had rallied 192% over the preceding twelve months before retreating roughly 20% from its peak. Samsung Electronics, despite reporting better-than-expected quarterly profits, slid 6. 8% for a second consecutive session. Hong Kong's Hang Seng was the sole major index to rise, gaining 3%.

Sara Perring, head of APAC cash equity sales at JPMorgan, attributed the Seoul sell-off to profit-taking concentrated in artificial-intelligence and semiconductor stocks, warning that elevated volatility and continued foreign selling should be expected in Korean equities in the near term. Whether two million barrels threading the strait each day is enough to keep the ceasefire's economic logic alive remains the question that no summit communiqué has yet answered.