I stand corrected sir
The German Shepherd's popularity was greatly due to the soldiers of WW1 lauding the dogs' agility and remarkable behavior during the War (on the side of Germany, to where the dog belonged), although the dogs were present and bred outside of Germany as well. However, towards the end of the war and for a few years after, especially leading up to WW2, there was a universal rise in
Anti-German sentiment. It was felt that the word 'German' in the dog's name could hamper the breed's popularity. So, the breed was renamed to
Alsatian, after the French-German border city of Alsace. This was immediately towards the end of the First World War.