Mussolini's government has really changed the country, and Italy took part in the first world war. In 1920s there were also climate changes.
The treaty of versailles declared Germany guilty of aggression.
Germany was forced to pay 33 billion dollars and many parts of it like Alsace lorraine, coal mine at Saar were given to France.
Moreover it had to supply huge amounts of coal to Belgium and Italy as well.
Its army,navy and ships were reduced.
In short, it had to take over the blame and responsibility of the World War1