I can't remember where I read it, but I think it was CNN. The article basically said that World War I ended after Germany finished paying off its war debts "last week". That was in September/October. I distinctly remember showing my history teacher this because we had just been reviewing World War I.
First: A war is generally considered to have, de facto, ended at a final cessation of hostilities (Nov 11, 1918 in this case).
Second: A war is considered de jure ended upon enacting a peace treaty. Which was effectively upon German ratification with the Treaty of Versailles but technically upon the date of ratification by each signatory nation or of a separate treaty/legislation as was the case with some countries. Or the dissolution of the participants.
Reparations are an ongoing part of the peace agreement, not a continuation of the war. Just like, if you buy a car, you own the car upon buying it, not upon final payment (though in this case the creditor may have rights to your car under the loan, that would change ownership again, just like any war in response to refusal to pay reparations would be a separate war).
Third:
Following WWI, Germany issued bonds to raise funds to pay off its war debts, among other things.
Germany ceased paying reparations in 1933 and Hitler repudiated the foreign debts noted above.
The reparations were effectively forgiven following WWII, though I am not sure if anything was officially done to forgive them.
The West German government agreed to pay the foreign debts of Western countries repudiated by, or incurred under, Hitler in exchange for certain international concessions (including entry into the WTO, I believe). This included debt that was used to pay for war reparations.
In October 2010, the last bonds of this debt was repaid by the German government.
