The head of the World Trade Organization (WTO) has said that new tariffs are causing major disruption to global trade and weakening long-standing rules. WTO Director-General Ngozi Okonjo-Iweala told Reuters on Tuesday that only 72 per cent of world trade is now conducted under the organisation’s “most favoured nation” (MFN) terms, down from about 80 per cent earlier this year. The MFN system requires members to treat one another equally. “We’re experiencing the largest disruption to global trade rules, unprecedented in the past 80 years,” Okonjo-Iweala said in an interview marking the start of her second term as WTO chief. She added, “So it’s not surprising that some would question the global trading system and its predictability. As long as the majority of trade is taking place on MFN terms, I think we should celebrate that. We’re a long way from 50%.” The fall follows US President Donald Trump’s decision this year to impose higher import tariffs on many of America’s trading partners. Okonjo-Iweala said the effects of tariffs may become clearer in 2026 as the current boost to global trade, driven by stockpiling of goods earlier in the year, slows down. “Possibly down the line, we’ll begin to see some other impacts, as the goods in the warehouses are exhausted and impacts begin to come in,” she said. “But we’ll see next year. We still anticipate some growth.” The WTO raised its forecast for global trade growth in August, from 0.2% to 0.9%, citing the strong activity in the first half of the year.