“Iran’s malign activity is both destabilizing in the region and supports other malign actors like Russia,” said Matthew G. Olsen, the assistant attorney general for the national security division of the Justice Department.
When Mr. Olsen traveled to Kyiv in November, Ukrainian officials presented him with evidence of American technology being used in the Iranian-produced drones that had attacked Ukraine. He said the visit had expanded intelligence sharing between the countries to bolster the American legal investigations.
American officials said it was hard to judge the direct effect of the export controls. Russian production of missiles, for example, was initially slowed by export restrictions. But as Moscow refocused its economy on wartime manufacturing, its missile-production level returned to, then exceeded, prewar capacity.
Iran’s drone production has fluctuated, potentially because of U.S. pressure on its supply chain. And American officials say they are at the least making it far more expensive and difficult for Iran to supply both its proxy forces and Russia.
“When we’re enforcing sanctions and export control laws, we want to impose costs on the bad actors, including Russian and Iranian actors,” Mr. Olsen said. “We want to charge them, out them publicly and, if possible, arrest them.”