President Trump 's decision to suspend a controversial maritime law during the Iran war has made it easier to ship oil across the U.S. — and now he wants to keep it that way, according to U.S. officials. Why it matters : Known as the Jones Act , the 1920 law raises the cost of shipping between U.S. ports because it requires goods to be carried on American-flagged vessels, which are in relatively short supply compared to the global supply. Trump issued a 60-day waiver from the law on March 18 to make shipping oil easier in response to rising fuel prices from the Iran war. Zoom in : Since then, 40 tankers have been able to deliver oil —or are in the process of doing so— between U.S. ports from California to Texas to Florida and Alaska, increasing the de facto fleet by 70% and helping to reduce costs as a result, according to data provided to Axios by the White House. Total American oil shipped by these foreign-flagged vessels under the waiver: 9 million barrels and counting.…