>>17810567>russia and the middle east those things happened decades apart
Russia was conquered 20 years before China and the Middle East by an old Subutai in the reign of Ogodei
unlike the Caliphate and the Song the Eastern Europeans were politically divided and incapable of deploying the much larger armies the Chinese and Middle Easterners could
the push into Europe was more about internal politics than anything, picking an easy target and kicking court rivals of Ogodei to somewhere very far away from Karakorum
Subutai fucking hated Ogodei because he rightfully saw him as a retarded drunkard pissing away his father's wealth, Ogodei also wanted to kick out Juchi's lineage which he considered illegitimate bastards despite Genghis Khan publicly forcing everyone to acknowledge Jochi as his legitimate son, he also sent along some of the more troublesome princes
by contrast the Middle Eastern and Song China expeditions were launched 20 years later during the reign of Mongke, the Song held out longer for a variety of reasons
>Song had a larger population >Song had better natural defenses(Yangtze River to the north, Mountains to the west)>the Mongols were divided trying to push it both directions at once>Mongols had local support in the Middle East, local Christians and polities like Armenian, Georgia and the Crusader States helped them>the Caliph Al-Musta'sim was fucking delusional and thought the entire Muslim world and Muslim Mongols would rise up to support him for reasons>Kublai just wasn't as good a general as Huleguthe Mongols under Mongke just wanted to brute force China into submission, it was under Kublai after they set up the Yuan Dynasty(he retroactively gave his family from Yesugei onwards Chinese imperial names) and claimed to have the mandate of Heaven all along that he started making some real headway into eroding the Song's powerbase. By making his rule palatable to the Chinese this seriously harmed Song legitimacy and let to their collapse.