Morgan Stanley warned that a full or partial U.S. diesel export ban could reduce refinery throughput and ultimately raise gasoline and diesel prices, even as European diesel prices moved above U.S. levels on concern that restrictions would worsen supply shortages. Farmers face diesel prices of $6 to $7 per gallon through 2027 or longer amid conflict-related Gulf disruptions, record refinery margins, constrained refining capacity and Europe’s reliance on U.S. cargoes. President Donald Trump backed consideration of restrictions on September 22, while Treasury Secretary Scott Bessent said officials were assessing whether a full or partial ban was feasible. Energy Secretary Chris Wright has opposed the proposal, warning it could lift U.S. gasoline and global diesel prices, and has expressed skepticism that a ban would be effective. Prediction markets put the chance of an announcement by September 30 at 6%, down from 16%, while assigning a 22% probability to an announcement by October 31. A separate market put the odds of crude oil reaching a new all-time high by September 30 at 0.4%, indicating that diesel-specific supply concerns have not translated into expectations for a broad near-term oil-price surge.