France recently cooperated with the U.S. and arrested an Iranian engineer (Majid Kakavand) sought for smuggling American military electronics. It's suspected the Kakavand was arrested mainly to pressure Iran to release a French citizen held in an Iranian prison. Even if the French do eventually return Kakavand to Iran, another smuggling operation has been burned, and Kakavand is, in the meantime, being interrogated.
Meanwhile, the arrest of Kakavand in France is just another instance of international cooperation in taking down Iranian weapons smuggling efforts. Many Western nations have become more aggressive in this area of late. Australia recently stopped a shipment of pumps that, it turned out, were capable of being used in nuclear power plants (as well as for more benign uses). Iran has been quite blatant about buying dual use equipment, and then openly using the stuff for military purposes. That bravado is backfiring.
Ever since the U.S. embargo was imposed in 1979 (after Iran broke diplomatic protocol by seizing the American embassy), Iran has sought, with some success, to offer big money to smugglers who can beat the embargo and get needed industrial and military equipment. This is a risky business, and American and European prisons are full of Iranians, and other nationals, who tried, and often failed, to procure forbidden goods. The smuggling operations are currently under more scrutiny, and attack, because of Iran's growing nuclear weapons program. But the Iranians simply offer more money, and more smugglers step up to keep the goodies coming.
The U.S. has gotten more aggressive, and successful, at shutting down Iranian smuggling operations. Not just by bribing the smugglers themselves, but also by getting the cooperation of nations the smugglers operate out of. This has been so successful that most of these smugglers no longer feel safe working out of Arab Persian Gulf nations (especially the United Arab Emirates). As a result, more smugglers are operating out of Malaysia, and the U.S. is trying to shut down that activity. America also monitors the international banking network, seeking signs of smuggler activity, and leaning on the banks involved, to step back.