Question: What countries did the western front run through?
Disambiguated questions and answers: question: What countries did the western front run through in World War I?
What countries did the western front run through in World War II?
answer: Belgium, north-eastern France, Alsace-Lorraine, Luxembourg, and western Germany
Denmark, Norway, Luxembourg, Belgium, the Netherlands, the United Kingdom, France, Italy, and Germany
Natural Questions answer: Belgium
Alsace - Lorraine
north - eastern France (from the Wikipedia article "Western Front (World War I)")