The release Saturday during a prisoner swap of four Americans held by Iran, including the reporter Jason Rezaian and Christian pastor Saeed Abedini, is certainly welcome news. But the details of this deal, arranged after a year of secret negotiations, are troubling.

In exchange the U.S. freed seven Iranian men, six with dual American citizenship—though they seem to have decided against returning to Iran. Most were charged with export violations: in other words, smuggling goods and technology, including those with military...