Donald Trump threatens new Iran sanctions, heightens oil market risks

President Donald Trump called on Congress to add tariffs targeting Iran into the Lindsey O. Graham Sanctioning Russia Act on July 29, bundling two of Washington’s most contentious foreign policy fronts into a single legislative package. The Russia sanctions bill had already sailed through the Senate with an 86-12 vote, making it an attractive vehicle for Iran-related measures that might otherwise face a slower path on their own. The move comes against the backdrop of what has become the most serious confrontation in the Strait of Hormuz in years, with renewed Iranian attacks on commercial vessels prompting the US to reinstate naval blockades and revoke earlier waivers on Iranian oil exports. Oil prices, which spiked sharply earlier in 2026, have since settled into the $80 to $85 per barrel range for both WTI and Brent. A diplomatic deal that didn’t stick On June 17, the US and Iran signed a memorandum of understanding that was supposed to guarantee safe commercial passage through the Strait of Hormuz for 60 days. Iran violated those terms. The details of the breach prompted Washington to snap back sanctions in early July, reinstating the very restrictions that had been relaxed as p...