Why is it that when two men fight a duel, one of them inevitably dies? I first encountered a variation of that quote in a fantasy series called A Song of Ice and Fire. Two members of the nobility, one a knight, the other a queen, were discussing matters of warfare. And the answer to that question is the ultimate differential between two civilizations.
In 19th century Japan, Commodore Perry of the US Navy forced open Japan to international trade on the strength of his fleet. When Japan's upper class saw what happened, they were determined to bring Japan into the modern world and were resolved into turning their country into one of the Great Powers of the world. What followed was a period called the Meiji Restoration.
During that period, the Japanese copied anything and everything about Western culture. They recruited Western businessmen, military officers, and political leaders to teach them the ways of the West. Ranging from things like military organization, technology, and even culture, the Japanese completely reinvented their society. Japan even adopted baseball as their national sport. Because their leaders were so unsure of what really made Western society superior to the traditional powers of the East, they wanted to copy everything in Western society. They even shed their traditional kimono for the traditional suit.
And it worked. 40 years later, Japan fought and decisively beat the Russians in the Russo-Japanese war. With their modernized army and strong internal economy, they were able to martial the resources, the weapons, and the men needed to overpower the Russian Empire in Korea and Manchuria. The Western powers took notice and grudgingly accepted Japan as a great power in the prevailing Westphalian system.
The real question is what was the real "secret sauce" that enabled Europe and the United States to completely dominate world affairs? In other words, what were the things that Japan had to emulate in order to become great themselves, and what were the things that they didn't really need to do. For example, it was probably unnecessary to adopt baseball and suits. But the technology, business organizational philosophy (Taylorism, in particular), and military training were probably indispensable in Japan's quest to become a great power.
Whenever two opposing organizations become locked in combat, one will eventually prevail. And then the postmortem begins for both sides (and independent observers). People will attempt to explain why one side won and why one side lost. But hindsight, in these instances, is not 20/20. Take for example the post-election analysis we currently see being churned out by the triumphalist media (who were in the tank for Obama from the very beginning). It's full of truisms, cheap shots, and jeering.
But the problem is that nobody can be proven right or wrong on the issue. You can't rerun the 2012 general election over and over again, change some inputs and variables, and then see the end result. You only get one shot at it. So when one side wins, they tend to believe that everything they did was necessary to push their candidates over the top. When reelection rolls around, the people riffling through their rolodexes are going to call upon the operatives and advisers of successful political campaigns.
It's why people like George Stephanopoulos and James Carville still have gigs on TV. They put Clinton over the top and Clinton was seen as the modern Democratic success story. His success casts an aura of success over the top advisers and operatives who worked on his campaign. So people will naturally think "those guys knew what they were doing and they probably know what's what now". Even if that's not really what happened.
In the book, the knight told the queen that sometimes it's impossible to tell what really causes one person to win a duel over the other. It could be the meal that they ate the night before. Or a wet patch of grass that one of them slips on. Or it could be that one is simply a better fighter than the other. But once the postmortem is conducted, the winners will inevitably conclude that it was mostly their skill and virtue that carried the day, even if it was mostly chance and circumstance.