I am rivals with Yuan Shao, but we tolerate each other, play at alliance, for there is long personal history between us. To betray that history would risk the wrath of mutual allies and old friends, and do terrible things to our reputation. So we glare, and tensions rise, and we race to take valuable territory from mutual foes, but we remain peaceful and our alliance strong enough.
But Yuan Shao dies, fighting bandits in the north, and his sons have no such compunctions. The Yuans vassalize their old foes and, as I march upon Dong Zhou, declare war. Now I’m at war on three fronts, against the Yuan in the east, Dong Zhou in the west, and a variety of vassal states to my north. I strike deals and manipulate some smaller states into fighting the Yuans, distracting his armies and giving me time and space to plan my next move. It would not have worked against Yuan Shao, too well loved by many of the men and women who now besiege his border territories, but his son has no such reputation.
This is the diplomatic world of Three Kingdoms: Total War, and it has helped turn Three Kingdoms into the best game in the series.