At the moment, it's not certain why Cartwright is receiving the pardon. He was the Vice Chairman of the Joint Chiefs of Staff from his nomination in 2007 through to his retirement from Marine Corps service in 2011, but he wasn't Obama's golden boy. Cartwright was denied the top Chairman spot in 2011 in part because of questions surrounding his staff management practices, including an alleged (though never punished) "unduly familiar relationship" with a female Captain.

One theory is that the outgoing White House administration wants to put a lid on discussion of Stuxnet. The Washington Post claimed that the investigation into Cartwright ran aground when officials realized they might have to confirm details of the malware in order to secure a conviction. That would have been particularly problematic at the time, when the US was negotiating the eventual Iranian nuclear shutdown agreement -- did it really want to admit to a cyberattack at such a critical moment? We wouldn't rule out any motivations at this point, but the guilty plea and pardon might spare the government from disclosing secrets.