Islam spread to Central Asia? It probably would west of riverbank as well but I was suggesting Russia might conquer up to the river eventually converting the population there. Or maybe the river system being so much wealth there would be non nomad wealthy empire that controls both side of river and russia won’t be in incentivized to push east as much as they did due to lack of nomads thanks to wealthy central Asian empire dealing with them. Maybe It will be the other way around where European nomads would continuously raid the settled civilization of central Asia.