Assange perpetuates these ideas for publicity. Snowden likely fears for his safety (rightfully so; Trump's CIA pick has said he wants Snowden dead), but seems to be much less hysterical about hitmen and death.

It would probably be done to

1) get revenge (human nature)

2) scare other potential whistle blowers

Odd that, say, Daniel Ellsberg has lived to be 85 and has not been hit by a ninja CIA bus. No NSA anvil has fallen on James Bramford (age 70). And there are dozens of others you can think of. There's next to no evidence the US government operates in the way you assume with respect to such people. Why does Snowden suddenly get his own squad of assassins?

And strategically, assassinating Snowden is about the worst possible move for a US linked agency since (i) it makes them look bad, even to some of the people who think Chelsea Manning got off lightly and (ii) it makes Snowden's revelations interesting to a whole bunch of people that don't read Hacker News and think that articles about email monitoring sound incredibly dull.

You don't have to believe that every US chain of command in every theatre of operations has qualms about "disappearing" people suspected of quietly leaking secrets to think that causing an international incident over a public figure like Snowden, even if the assassins were guaranteed to succeed and not perish in a firefight with Russian cops called by an FSB security detail, isn't going to do them any good.

I can't think of dozens of living whistleblowers who blew the whistle on the CIA or NSA, or both. Which group were you referring to?

There've been several just in the last few years, Ellsberg was a genuine whistleblower, the NSA wanted to stop the publication of Bramford's work. On top of that there have been multiple genuine, grade A, real spies. They get caught, tried, convicted and imprisoned - they don't end up dying in car accidents or even accidentally falling on a pair of scissors in prison.

I think that the risk of Assange ending in the US via Sweden, if he leaves the embassy is very real.

Maybe but that's hardly assassination.

They'd have much more incentive to wipe him out if he hadn't leaked the documents already. After the leak, there's not much further damage he can do.

You're assuming he's released everything he has... and he didnt. He censored stuff, he left it up to news outlets to pull out newsworthy stuff and not share things likely to compromize national security... those things are out there still... and he has them, so yes, he still has damage he can do... i believe he has no interest in doing said damage, but the potential is there

The damage is already done. It's much more likely that every interested intelligence organization has already got their hands on everything he took (because that's their job) than 'US intelligence is plotting an assassination attempt' (not really their job).