The "stab-in-the-back myth" refers to a belief that emerged in post-World War I Germany, suggesting that the German military did not lose the war on the battlefield but was betrayed by civilians, particularly socialists and Jews. This narrative was used to explain Germany's defeat and to shift blame away from military leaders. This myth gained traction among nationalist groups and contributed to political unrest in the Weimar Republic. It played a significant role in the rise of extremist ideologies, including those of the Nazi Party, which exploited these sentiments to gain support and justify their actions during the 1930s and 1940s.