Anyway, we'll see how things play out. If our guy is smooth enough to get everything we want without fighting, that's great. But if say, the neighponese refuse to interact at all, and we find that their claims of a great dragon backing them are bull, why wouldn't we search for some flimsy claim to install a puppet rulership or just outright conquer in time?
Assuming that from the viewpoint of those in character the benefits outweighed the costs. Especially if they got strategic resources we don't.