For America's intelligence and diplomatic apparatus to work, it needs to be able to do secret things whose disclosure would be damaging to American interests. And it needs to be able to bind government employees and contractors to not to make those disclosures. Snowden broke his commitment to safeguard a wide variety of secrets, many of whose disclosure was in no apparent public interest.
Snowden's wide-ranging disclosures of secret documents did reveal some matters of genuine public interest, which should never have been secret, particularly the extent of the National Security Agency's collection of electronic data on Americans. They also made clear that Director of National Intelligence James Clapper lied to Congress about what sort of data the NSA was collecting (tortured explanation from DNI General Counsel Robert Litt notwithstanding). This has had a positive effect on the public discourse, which I acknowledge.
But the key term in my description of Snowden's leaks is "wide-ranging." Snowden also disclosed a large number of documents that had nothing to do with Americans' privacy. His disclosures include information about U.S. hacking of Chinese computer systems; U.S. spying on Russian President Dmitri Medvedev during the 2009 G20 summit London (and simultaneous British surveillance of other targets); the existence of 80 NSA listening stations around the globe, including one in Berlin which was used to monitor the cell phone of German Chancellor Angela Merkel; and much more.
Often, far from revealing wrongdoing, these disclosures simply showed how the NSA doing the job it is supposed to be do. These disclosures make it harder for the NSA, our other intelligence agencies, and the State Department to do their jobs, negatively impacting U.S. foreign policy goals.
Snowden's defenders often say that his disclosures haven't had any demonstrable negative impact on U.S. security. That relies on too narrow a definition of "security," along the lines of "did they enable a terrorist attack?" The Snowden disclosures have worsened our relations with a variety of our allies and competitors, notably including the Germans, the Russians, and the Brazilians. The U.S. invests a lot of money and energy in fostering favorable international relations; if damage to those relations is irrelevant, there's a lot of diplomacy we can just stop bothering with.
Ryan Lizza suggests that if the U.S. wanted to avoid international incidents, we shouldn't have tapped Merkel's phone. That's probably true in the specific instance. But there are some things U.S. intelligence agencies should be doing that would annoy our allies if they were disclosed. There are many more whose disclosure would annoy our competitors. The Medvedev surveillance falls into this category: It's something the NSA should have been doing, and something that should have been kept secret.
Unless we fundamentally alter what intelligence agencies do, secrecy will be important to their operation - Eric Schmidt's "If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place" rule can't apply to the CIA.
If you think our intelligence agencies shouldn't need to keep their operations secret (and therefore Snowden's disclosures were not damaging) then you are endorsing a very radical critique of U.S. foreign policy. Some people endorse that critique, including Snowden himself; I think most of the reporters implicitly endorsing it have not thought it through very hard.
If Snowden's disclosures had been tightly limited to information about how U.S. intelligence agencies collect private information about Americans, I'd be more sympathetic to calls to let him off. And I still don't think he needs to be executed or imprisoned for life; a long sentence signifying the severity of his crimes, perhaps 15 years, would satisfy me. As Paul Carr notes, all sorts of criminals get plea bargains, and Snowden could have one too.
The sentence in such an offer has to be long enough to deter future Snowdens from leaking. The government keeps too many secrets, but I trust the government to decide what needs to be secret more than I trust rogue contractors with security clearances to decide what should be disclosed. As Snowden's trove shows, even a useful disclosure is likely to be bound up in an array of harmful ones. So a few years in a minimum security prison followed by release into living martyrdom won't cut it for me; I fear it would encourage copycats.
Maybe that makes me a "fascist," though I'm pretty sure it just makes me someone who thinks the U.S. needs secret intelligence operations, and needs to punish people who violate their agreements to keep information about those operations secret.