I don't think Russia is remotely afraid of the US! They're completely ruthless, devious and with very different ideas and attitudes to the West. The destruction of Syria is reminiscent of Europe at the end of WW11. The starving displaced children/people, devastated cities and countryside. Easter European countries were more afraid of the Russians, their liberators, than they were of the Germans. As for the Germans, what happened to them courtesy of the Russians, is too horrible to talk about, thus their desperation to surrender or escape to an American/British/French Zone. Make no mistake the Russians are ruthless and to be greatly feared. I am old enough to just remember it.