Generally dissidents have more in common with the country they're fleeing to than the one they're fleeing from but that's not the case with Snowdon. He's not a communist sympathiser, he's closer to being an American patriot who has done something his government may disagree with because he wants his country to be better. Simply put he's in Russia because it's there or Guantanamo Bay.

On the Russian side Putin has no sympathy whatsoever with the principals Snowdon stands for. Putin is a former spy with a penchant for locking up or oppressing those who oppose him. His logic runs no further than my enemy's enemy is my friend. If Snowdon was had revealed similar information about Russian intelligence Putin would be first in line to have him locked up or worse.