World War I film propaganda

Nations were new to cinema and its capability to spread and influence mass sentiment at the start of World War I. The early years of the war were experimental with using films as a propaganda tool. Eventually, they became a central instrument for what George Mosse has called the "nationalization of the masses" as nations learned to manipulate emotions to mobilize the people for a national cause against the imagined or real enemy.

Source: Wikipedia — World War I film propaganda (CC BY-SA 4.0)