What makes a civilization real to its inhabitants, in the end, is not just the splendid edifices at it centre, nor even the smooth functioning of the institutions they house. At its core, a civilization is the texts that are taught in its schools, learned by its students and recollected in times of tribulation.
The Japanese had no idea what elements of Western culture and institutions where the crucial ones, so they ended up copying everything, from western clothes and hair styles to the European practice of colonizing foreign people. Unfortunately, they took up empire-building at precisely the moment when the cost of imperialism began to exceed the benefits.
It was an idea that made the crucial difference between British and Iberian America – an idea about the way people should govern themselves. Some people make the mistake of calling that idea ‘democracy’ and imagining that any country can adopt it merely by holding elections. In reality, democracy was the capstone of an edifice that had as its foundation the rule of law – to be precise, the sanctity of individual freedom and the security of private property rights, ensured by representative, constitutional government.
Historians are not scientists. They cannot (and should not even trying to) establish universal laws of social or political "physics" with reliable predictive powers. Why? Because there is no possibility of repeating the single, multi-millennium experiment that constant to the past. The sample size of human history is one.