When reparations payments first came due in 1921, the German economy was in bad shape and the government resisted payment, while the German right opposed paying them at all.
Germany receives the Treaty of Versailles and is given the choice of accepting the treaty as it stands, or restarting the war.
Imposing an indemnity on the defeated enemy after a war was a longstanding practice. At the Paris Peace Conference, reparations were supposed to be something more just and civilized: a charge for losses to civilians during the German occupation of Belgium and France.