Why did the 1919 Treaty of Versailles dismantle the German and Austro- Hungarian empires but not other empires?

Though representatives of nearly 30 nations attended, the peace terms essentially were written by the leaders of the United Kingdom, France and the United States, who along with Italy, formed the “Big Four” that dominated the proceedings. The defeated countries—Germany and allies Austria-Hungary, Turkey and Bulgaria—weren’t invited to participate.
In the end the Allies agreed that they would punish Germany and attempt to weaken that nation so much that it wouldn’t pose a future threat. Germany’s representatives had no real choice but to accept the terms.