One of the best explanations I've read of the rise of Imperial Japan and their ethnocentric imperialism, and how the hell the country went from the Meiji reforms to that... thing
, was actually the first few chapters of James Bradley's Flyboys
He lays out the entire chronology from Japan's first European contact with the Portugese, to the forced opening of ports by Perry, to how Japan's society and cultural consciousness was impacted by the different events of colonialism as it rose and fell, and how the centuries of political, philosophical and military insight accrued over the years by the samurai class was basically lost in translation within a single generation.
The real wisdom, experience, and insight behind the mythos and philosophy of bushido
wasn't passed on, and the next generation - the generation in charge of Japan in the 1930s and 1940s - only knew the grandiose myths and Japan's cultural proclivities of racial superiority.
Basically, the entire leadership of a nation seriously believed their predecessor's own hype because they never were properly taught the truths behind those myths.
And then they went and started invading countries believing their warrior spirit actually made them superior and invincible.