The idea that either of them are at risk of being whacked is utter tinfoil-hattery. The worst Snowden has to fear is being convicted and jailed, and it says a lot about him that he fled to Russia of all places instead of manning up and facing trial.
Snowden didn’t choose Russia as a destination. He left Hong Kong for Latin America and got stranded in Moscow when the U.S. revoked his passport mid-transit. He spent weeks in the airport transit zone while seeking asylum from multiple countries; Russia gave him temporary asylum after that.
“Manning up and facing trial” sounds fair in theory, but under the Espionage Act there’s no public-interest defense. He’d be barred from explaining motive or the public value of the disclosures, much of the case would be classified, and past national-security whistleblowers have faced severe penalties. That’s why he sought asylum.
Being convicted and jailed can be pretty bad. Didn’t Robert Hanssen end up in Florence ADMAX until he died [0]? And, maybe a more direct comparison, Wikileaker Joshua Schulte [1]?