And they were allies. It was obviously very foolish for Nazi Germany to invade Russia. But Hitler had motives and interests that don’t exist between Turkey and Russia. Russia does not want to occupy Syria, they just want Assad to stay in power so that they have a port and Iran has a client state. Russia would be better off with an intact Turkey than an independent Kurdistan.
Don’t be so sure. The difference between modern Russia and the Soviet Union, is the influence of the Russian Orthodox Church. And reclaiming Constantinople has been the goal of the Orthodox for centuries.