Or aggressive/peaceful by turn, depending on what its leaders calculate will achieve their goal of regional -- and then worldwide -- hegemony.
I think China will be peaceful so long as no one is seen as acting as a colonial power dictating to the Chinese or put them in a situation where they will lose face in front of the entire world. I believe that it’s in the best interests of the rest of the world to ensure that China does not feel threatened, while at the same time, not letting China throw their weight around in diplomacy.