North King said:
Besides which, I doubt any European army could defeat the Mongols in the field, so they could just starve them out if need be.
This statement shows considerable ignorance. No large Western European army had ever faced the Mongols in battle. Liegnitz was a mess (in all respects much like Nicopolis in 1396; thanks to the immense ignorance, confusion and extremely poor coordination among the Europeans) destined to be a failure because the mixed Christian force (largely Polish light cavalry, some infantry and a small contingent of heavy cavalry) knew nothing about their enemy and fought without a clear chain of command. Surely, you cant possibly judge the European system on a few isolated mishaps. Granted, there were cases of hysteria and poor judgment, but I don't think there were all that many engagements where the European military system as such failed against an eastern army of comparable size and strength. It would be false to automatically attribute the failures of these battles to any inherent flaw in the European way of waging war. But Mohi and the accompanying skirmishes in Hungary really present an entirely different picture. The Hungarian army, while still relatively poorly equipped by Western standards and commited to battle under unfavorable conditions, inflicted very heavy casualties on the Mongols before collapsing. The Mongols seem to have won only because of their extreme determination and only at a very high cost. To stress this again: it was probably the losses suffered at Mohi that effectively hindered the Mongol expansion and reduced the power of the Golden Horde.
And given the amount of experience with steppe warfare, and it is fair to say the Europeans knew what to expect from the Mongols. They had scored great victories over similar nomadic opponents (i.e. Saracens, Parthians, Huns, Avars, Moors, ect.). For all practical purposes, the Mongols were not so different than these other steppe dwelling peoples. All of them practiced the same type of pastoral transhumance lifestyles, had the same clan-tribal system of government, very similar religious belief system and fought from horseback in the same manner using composite-compound recurved bows as did their predecessors. Even their tactics: encirclement, sweeps, feigned retreat and ambush, were previously used by earlier kindred steppe peoples. The persistent idea of superiority of horse archers to European armies is merely a myth. There already were ideal counter-measures - the tactics developed to deal with Eastern horse archers over centuries. The Carolingians learned about them when fighting the Avars, Lombards and Byzantines. The Germans picked up some experience the Magyars. A fair number of European mercenaries served in the Byzantine and Muslim armies (in Spain or the Middle East). Even if we leave the Avars and Magyars aside, Western Europeans had been fighting horse archers in the Crusades for nearly 150 years - and that was before Batu's raid. Pope Innocent IV had a fair number of people at his court well versed in Eastern warfare, especially Friar John of Plano Carpini, who had plenty of opportunities to observe Mongol military practices, since he was part of the first Papal mission to Karakorum, in 1245-1247. Louis IX of France had ample opportunity to experience the effects of a military system inherently similar to that of the Mongols during his active stay in Egypt. He apparently had parituclar extensive knowledge of Saracen warfare. Preparations for the Louis' two crusades were very serious and display an in-depth familiarity with the Eastern military system. Added to this one can look at the pattern of Mongol raids into central Europe during the rest of the high Middle Ages and late middle ages; hardly a string of successes. The Lithuanians especially made good use of their terrain to neutralize the raids, and launched an impressive numbers of raids into Russian Mongol dependencies that were met with little response. Since the Europeans had some experience fighting predominately nomadic armies, it's fair to expect that they could develop effective countermeasures against a hypothetical Mongol invasion relatively quickly.
Oh, and the terror advantage would defiantely play out after the Mongols sacked a few cities in, say, Belgium, and killed a few million.
A lot of problem with this. Firstly, IF and it's a big IF the Mongols decided that the way to go in Europe was widespread genocide, AND get away with it, then what would be the point? Ruling over a desert isn't really any fun. Secondly, how would they get away with it? There were castles EVERYWHERE in Europe. EVERYWHERE. And they were all filled with armed men. You can't just go rampaging everywhere and avoid all of them no matter if your army is all mounted or not. You have to eat, you get ambushed, you have to rest, you have to plunder. Third, there are only a few thousand Mongols doing all this. It's not like there is a Mongol for every european. And if they use auxiliaries, they lose their mobile advantage--which means that they can no longer outrun the European armies. How do they kill all the peasants anyhow? The way they depopulated Iraq was not by slaughtering everyone but by destroying the irrigation system. Europe relies on rainfall agriculture meaning that the Mongols have to win the hard way--knocking down castles. If they take over a region and start depopulating it, then not only will EVERY LORD AND KNIGHT IN EUROPE rush to the scene, but the peasants will just go into the forests where the Mongols can't chase them.