Germany was forced to pay for damages caused during World War I due to the terms of the Treaty of Versailles. The treaty, which was signed in 1919, placed the blame for the war on Germany and its allies, and required them to pay reparations to the Allied Powers. The reparations were to be paid over a period of 30 years, and the total amount owed was 132 billion gold marks, or about $33 billion. The reparations were a heavy burden on the German economy, and contributed to the country's economic problems in the 1920s and 1930s.