Disruptions in the Strait of Hormuz could force small and medium-sized enterprises out of global supply chains even after trade volumes recover, the United Nations Conference on Trade and Development (UNCTAD) said. SMEs account for 90% of global businesses, 70% of employment and 50% of GDP, while smaller companies have less capacity than larger rivals to spread rising energy, transport and financing costs across suppliers, markets and lenders. Small firms in developing economies spend 19.4% of import value on customs, brokerage and other compliance requirements, compared with 14.7% for large firms. Their average borrowing costs are about 15.8%, versus 10.3% for bigger borrowers. UNCTAD described the threat as an exclusion effect, in which firms cut production, postpone investment or leave value chains altogether. The U.S.-Iran war has raised energy bills, freight rates, insurance premiums and financing constraints, while Houthi attacks on southwestern Saudi Arabia could compound disruptions to Middle East energy supplies. UNCTAD urged governments to protect SME access to trade finance, liquidity and working capital and to monitor whether smaller firms retain market connections during shocks.