Natural resources. Oil & LNG (which America exports but much of Europe, China, and India import). They have Uranium fit for nuclear plants (so does Mali, which is why it’s a point of contention between France and Russia). Kind of crappy but still explosive weapons sales. The U.S., France, and China will sell you previous generation weapons that are better than Russia’s best stuff.
I mean, to vastly oversimplify, it’s a gas station with nuclear weapons and rocket scientists from the Soviet era. It’s not a diversified economy for a country so large. They export grain and shit like that but it’s a whole continent wide and they aren’t efficient about it.