The difference is that Russian state security is protecting him from deportation/abduction/assassination (while also surveilling him) to make sure they get to keep sticking their finger in America's eye.

If he leaves the Eastern bloc you can bet that the boys in Fort Meade will make contingency plans to sabotage his brakes/get him on trumped-up charges for something else a la Assange/otherwise ruin his day.

>The difference is that Russian state security is protecting him from deportation

that's a double edged sword; if the Russian leaders decide some day that they want to improve relations with the US by extraditing him then they might just do it.

That's true. I guess what the OP meant is that trait + being known in the US is what puts Snowden at greater risk in the US.