"The fifth line" on the Soviet passport which listed the bearer's "nationality" (what we would usually call ethnicity in English) was only removed from Russian passports in 1997. But Edward Frenkel was picked out as a Jew because of his surname even though his nationality was listed as Russian, like most children of mixed marriages between Russian and non-Russian parents.

What if Edward Frenkel's father had been Russian and his mother Jewish instead of the other way round? Well, the commander of the Soviet Air Force in Ukraine when the Soviet Union broker up was Kostyantyn Morozov, then Konstantin Morozov. He had a Russian surname and his nationality was listed as Russian. If it had been known that he had a Ukrainian mother and had Ukrainian sympathies, he would never have been given such a powerful post by the Soviet authorities. As it was, Morozov announced his allegiance to the pro-independence cause to become the first defense minister of an independent Ukraine and to establish the Ukrainian armed forces.

Would the breakup of the Soviet Union have gone differently if all the high-ranking generals in control of Soviet forces in the biggest non-Russian republic were pro-Russian? It makes you wonder how many accidents of history can be traced to the arbitrary custom of inheriting surnames from fathers.