Look at this map which was the front lines on the Western Front on November 11, 1918.

https://blogs.loc.gov/maps/2018/11/mapping-armistice-day-11-november-1918/

That red line which represents the opposing lines of trenches, runs from Holland to Switzerland and is entirely in Belgium and France, with only a tiny southern part in Germany. The German veterans saw that map too, and came to the conclusion that they were not losing the war when the government surrendered. That is a totally rational observation, because millions of German troops were still in a country they had invaded when they were told they had lost. These same millions of veterans, including Hitler, formed the National Socialist and other nationalist parties that were later folded into the NSDAP primarily to get revenge for what they felt was their betrayal right after the war ended. No one had to be talked into something later on, because getting revenge was the very essence of the Nazi program. World War I veterans formed the cadres of the earliest Nazi party, and the leadership was full of them. Without those veterans, there is no Naziism. Consider what they saw and did in the trenches, and how that prepared them for what they did later. As horrible as this is to imagine, they were quite successful in extracting this revenge since they made the whole world suffer.