How did Hitler break the Treaty of Versailles?
- 1933: Germany ceased paying reparations altogether, though the original burden had been reduced twice in the 1920s and special provision had been made for only very small payments during the Great Depression. (I'd regard this as one of the less serious breaches).
- Began secret rearmament.
- 1934: Interference in the internal affairs of Austria.
- Germany began to build an air force.
- 1935: Re-introduction of compulsory military service for all able-bodied young men. Fivefold (!) increase in the size of the German armed forces. (Major breach of the treaty).
- 1936: Remilitarized the Rhineland, which had been remained German but been demilitarized under terms of the Versailles Treaty. (Major breach).
- 1938: Annexation of Austria - contrary to the treaty. (Major breach).
- 1939 (March): Annexed Memel.
In addition, there were the following actions, which weren't covered by the treaty:
- 1933 (October): Pulled Germany out of the League of Nations. In the 1920s Stresemann had managed to get Germany admitted and had ended Germany's international 'outcast' status.
- 1938 (September/October): Demanded (and got) the Sudetenland at Munich.
- 1939 (March): Occupied the rest of Bohemia and Moravia. Most of Slovakia set up as German puppet state. 1939 (July): Strident demands to Poland for Danzig and the Polish Corridor.
In 1926 when Germany joined the League of Nations it had solemnly accepted its western borders as final and had undertaken not to try to change it eastern borders by force.