President Donald Trump threatened to bomb Oman if it “gets in the way” of American plans for the future of the Strait of Hormuz. Despite the threat, Iran and Oman announced that they are nearing an agreement to open and manage a single corridor through the strait. While this statement doesn’t address tolling, Muscat has previously signaled that it would accept a joint fee-collection mechanism with Iran. This stands in direct opposition to promises from Trump that Hormuz will be “open, safe, and free.”

Operation Economic Outcast, the Trump administration’s campaign to cut off Tehran’s remaining financial lifelines, can offer an outlet for that frustration. Washington should tell Muscat that unless it ends its financial enabling of Iran and its proxies, Omani financial institutions will be disconnected from the U.S.-led financial system.