But, the official said, the United States has been challenged to enforce the sanctions without reliable help from allies and as traders play a “cat-and-mouse game” to avoid being tracked on the high seas. The official spoke on the condition of anonymity while the Iran talks were continuing.
U.S. Navy and Coast Guard ships conducting security patrols in the Strait of Hormuz and the Persian Gulf have been confronted by Iranian military vessels three times over the past month, heightening tensions that could, if allowed to escalate, threaten the delicate nuclear negotiations in Vienna. Twenty percent of the global oil supply — about 18 million barrels each day — flows through the strait.
Other world powers have been reluctant to enforce sanctions that were imposed, over their objections, when the United States left the nuclear deal in 2018. The most notable example came last fall, when the Trump administration declared it had reimposed international sanctions against Iran that the United Nations Security Council refused to recognize.
The United States has also warned that it could impose what are known as secondary sanctions on foreign buyers of Iran’s oil, which would cut them out of American markets and other transactions that are processed in U.S. dollars. That has spooked international companies that do not want to lose access to American banks and some analysts said that it has hurt relations between the United States and European allies who had hoped the nuclear deal would open new economic markets for their industries in Iran.
“If the United States tries to use sanctions for everything, and tries to tell the rest of the world what it can and can’t do, at some point other countries could well push back and say, ‘We’ve had enough of this,’” said Corinne A. Goldstein, a sanctions expert and senior counsel at the law firm Covington & Burling. “So I think the United States risks losing the power of sanctions by abusing their use.”
Since January, The Treasury Department’s Office of Foreign Assets Control has fined companies more than $2.1 million for violating its sanctions against Iran to settle or otherwise resolve yearslong cases, some of which began under President Barack Obama. The Treasury Department resolved about as many violations of Iran sanctions for all of 2020, including a $4.1 million settlement with Berkshire Hathaway after one of its Turkish subsidiaries was accused of selling goods to Iran and then trying to hide the transaction.
Elliott Abrams, who oversaw the drumbeat of sanctions against Iran toward the end of the Trump administration, said the penalties blocked revenues worth tens of billions of dollars to Tehran, limiting how much support Iran could devote to its nuclear and military programs, including its proxy forces across the Middle East.