“But we weren’t about to pressure the Euros into give up their colonies.”
And even less than that. The Japanese would have been happy with German colonial possessions in the Pacific. They were administered as part of German New Guinea and they included the German Solomon Islands (Buka, Bougainville and several smaller islands), the Carolines, Palau, the Marianas (except for Guam), the Marshall Islands and Nauru.
The Japanese expected to be cut in after Versailles as they were allies in WWI. And they had quite a history fighting Russia and the Soviets.