Japan was treated harshly and crushed for its imperialistic ambition while the Europeans continued their grasp on their colonies.
Step-by-step explanation:
Japan was trying to expand its sphere in colonies like the Europeans were wont to do in the world for centuries but their dreams were ruined with defeat in the war and then the treaty of Versailles.
They now understood that the European powers understood the empire as their own right to have and not some ting that the other empires should have to.
Only the European nations can have colonies to maintain their delicate balance of power and they can all unite to make sure that happens.
This is what Japan had to realize the hard way with the treaty.