Edward Snowden should be allowed to remain in Russia. If he returns home to the US, he will likely be prosecuted and sentenced to prison for a very long time. Chelsea Manning was sentenced to prison for 35 years and although was given clemency by Obama, has since spent 3 years in prison with two attempted suicide attempts.Trump has been clear that Snowden would not be welcomed in his presidency.
The asylum of Snowden to Russia should be allowed. Since Snowden is not welcome in the United States, he needs to have a country to accept him. It is still a question of treason, to consider the actions and secrets that Snowden released so he should not be accepted back into the U.S.
We may as well let Russia keep Snowden. The only thing that's going to happen if he comes back to the US is that we are going to spend a ton of money holding a trial for him, then pay for him to live comfortably inside a federal prison. We may as well just ignore him and leave him over there in Russia.
Relations between the United Stares and Russia are still quite tense at this point. It is right of the host country to grant or refuse it, regardless of the good or bad nature of the reasoning. If Russia decides to continue granting Snowden asylum in their land, there is little else that anyone can do without the use of force, and to escalate matters to those measures simply would not be worth it. If the U.S. officials wanted him so badly, why was he allowed to leave the country in the first place.