What??
It's was the U.S. government doing the espionage on that country which is harboring the person who ratted out the country committing espionage, which was the U.S. government.
LOL!
We would likely refuse to hand him over to Russia, and would also likely refuse to grant him asylum.
In other words, we would be telling Russia that we understand where they're coming from but that we will not act as an extension of the Russian government.
That's exactly what Russia is doing now with regards to the US.