No one expected the war to come so suddenly; in the normal course of events, such a large-scale war would not occur in the home world, but sometimes things simply aren't up to them.
After all, they had already built the Floating City over here, while other cities, due to being dispersed, could only rely on their own strength to conduct research. Thus, their development speed was very slow. Bringing the Floating City into existence is no easy task.
They required long-term research and experimentation, even with the support of a technologically advanced world, it still took a considerable amount of time.
The problem now was that they needed this time interval. If they allowed the other side to continue developing, by the time they completed their research, the other side would already have many Floating Cities. By then, their own people would have suffered great losses. There were also many special effects, which could easily trigger chain reactions.
