Why was Germany not allowed an air force leading up to World War 2?

(Note: Question Corrected from "WWI" to "WWII")

The Treaty of Versailles, which ended WWI, imposed many severe restrictions on Germany's military structure. Among these was a clause forbidding Germany from having armed aircraft. Obviously, history shows that Germany disregarded many of the Treaty's restrictions, as it had one of the largest and most advanced Air Forces in the world at the outbreak of the war.