it's a bit confusing, and you as the reader really have to draw conclusions on your own.
ch 6. so black-hair, despite knowing hisar(?) could be forced into allowing the revolt, used this chance to let the visars understand that the shadows of war is close upon them. whether hisar is innocent or not, he did not care, and went over to his province to suppress the uprising, but it turns out that the enemy empire's army, which exceeds his numbers, was behind him. if black-hair tried to suppress the revolters (the arabas), their fellow clansmen outside will def not stand for this, and so this would allow a chance for the empire to intervene with a just cause. i think.
ch. 19. solid plot without any contrived tropes. it's all about politics and the greater benefits before friends and stuff- basically nationalism. it's no coincidence that suleyman bey looks like the older version of mc, he's the more mature version who traveled and is actually competent (not to say mc isn't, but he is still naive in world politics).
ch 25. i cant deny it any longer...... im not entirely sure what's going on. all i know is that the political opponent is wayyy intelligent.
Shoukoku no Altair