The main effect of the Treaty of Versailles on post-WWI Germany was the imposition of heavy reparations and territorial losses, which contributed to widespread economic hardship and social unrest. Signed in 1919, the treaty held Germany responsible for the war, leading to significant reductions in its military capabilities and territorial claims, including the loss of Alsace-Lorraine to France and parts of Prussia to Poland. The heavy reparations placed an immense burden on the German economy, resulting in hyperinflation and contributing to political instability. These grievances ultimately fueled nationalist sentiment and social unrest, paving the way for the rise of Adolf Hitler and the Nazi party in the 1930s.