Interesting. Although this point of view might be a bit simplified, there&#x27;s another example of a weapon, which was both relatively cheap to make - and really hard to use unless the whole society was built around the skills required to use it.<p>Mongols! Light cavalry using composite bows was both unbelievably effective and hard to copy for everybody but steppe nomads. All Mongols were hunters, they practically lived with their bows on their horses. So the whole population could do warfare.<p>While back in the days, in both Eastern and Western Europe, contemporary warfare was rotating around heavy cavalry, and one can&#x27;t have too many knights. Even if somebody managed to gather an army more or less comparable to Mongol hordes - heavier cavalry would just be meat for lighter riders making circles around them.<p>Besides, feudal lands never managed to be centralized enough to counter mongols. In medieval Rus&#x27; the need to centralize led to the rise of Moscow - and it took quite a while anyway.