History teaches us the rise and fall of nations. Many of the social problems humanity faced today, along with their answers, could be found in history.
Humans were a race skilled at repeating themselves, yet never learning their lessons. But that was not entirely a bad thing. When a problem had been answered thousands of times, those who came later could always find the answer that suited them best among them all.
Looking across the long course of human history, there had been no shortage of wars where the weak defeated the strong and turned the tide against all odds. But when it came to the greatest disparity, the largest scale, the longest duration, and the most miraculous outcome, Batman could think of only one war.
Batman was more proficient in small-scale tactics, and personally, he did not favor large-scale warfare either. But that did not mean he had never studied it.
For someone with paranoia, he was always prepared for aliens to invade Earth and for himself to lead humanity in resistance.
Under such assumptions, Batman took matters to extremes. For example, the aliens might be far stronger than humans physically, possess more advanced technology, be better organized and disciplined, and hold an advantage in every aspect that transcended the ages.
And if he wanted to consider how such a war could be won, Batman, who had never personally experienced war, had no choice but to look through human history.
After searching through it all, there was only one war that met such extreme conditions. Thus, Batman had focused his research on that war.
And the more he studied it, the more he discovered that the larger the scale of a war, the less important external factors became. In the end, it still came down to the three classic