It is much easier to marry someone next door. Don't let anyone fool you. It is not easy. Mail can be iffy and quite slow. Russians are not necessarily the quickest to respond to a letter to even get it on its way.
Telephones can be down for periods of time.
Dealing with the INS is not always a walk in the park. And language and cultural differences can cause problems. While many Russians speak English, this is generally school English. They often need practice until they really are up to speed. One of our first couples had a problem when the man wouldn't accept the wedding rings from the jeweler as they didn't fit.