I always assumed that the game was telling you 'hey, guess what? For doing such a good job, everything that happens in Sword of Seals is your fault.' I mean, it talks about how Bern and Etruria went to war over that guy, and guess what happens in Sword of Seals? Bern and Etruria go to war.
I mean, that's not really the reason, but I always imagined it as such.