There are hundreds of millions of native speakers in many countries, so it's often hard to have absolute agreement on something. Sometimes it is a matter of choice whether we think of two things as one unit and singular or as two individual things. Here, I think there are two things (doing business in the US + doing business in Russia), but both Mike and I can imagine someone thinking of it as all one thing (doing business). I don't think there's a very strong case for using is, but I can see some people using it.