If the most famous U.S. government secret revealed by Edward Snowden had been the only one he divulged, deciding whether he deserves a pardon from President Barack Obama would be a tougher call.

Snowden famously disclosed in 2013 that the National Security Agency had been collecting Americans’ electronic metadata in bulk. The program was authorized only by a dubious reading of existing law, and when Congress debated the issue it insisted on changes to the program. So even though Snowden broke the law, he contributed to a worthwhile democratic debate.

But that’s not the whole story, as the University of Chicago law professor Geoffrey Stone has pointed out…