<P> During the Napoleonic Wars, France repeatedly fought on multiple fronts . For example, France fought the Spanish and Anglo - Portuguese army in the Peninsular War while fighting the Russian Empire at the same time during its invasion of Russia . Their main adversaries the British were also engaged on multiple fronts at various times, having also to contend with the United States starting with the War of 1812 in Canada, the Chesapeake Bay, and Louisiana . </P> <P> During World War I, Germany under Kaiser Wilhelm II fought a two - front war against French, British, Belgian, and (later) American forces on the Western Front while simultaneously fighting the Russians on the Eastern Front . Russia's participation ended in the First World War, when the Bolshevik leaders signed the Treaty of Brest - Litovsk with Germany in March 1918 . Germany had foreseen such a scenario, and developed the Schlieffen Plan in order to counteract being surrounded by its enemies . Under the Schlieffen Plan, German forces would invade France via Belgium, Luxembourg, and the Netherlands (the idea to go through the Netherlands was abandoned because of the country's neutrality), quickly capturing Paris and forcing France to sue for peace . The Germans would then turn their attention to Russia in the east before the Tsar could mobilize his massive forces . Due to several factors however, the Germans failed to achieve the plan's aims . </P> <P> The most famous example of a two - front war was the European theatre during World War II, when Hitler's Nazi Germany had to confront the Western Allies on the west and the Soviet Union to the east . The Germans were unable to repel either of the advances on the two fronts and eventually lost the war . While there were other contributing factors, such as the insufficiency of the Wehrmacht for a long war and the abandonment of blitzkrieg tactics because of fuel shortages and a rising need to defend territory, the two - front war was an important factor in deciding when the German military would be forced to surrender . </P> <P> The Allies, especially the United States, also fought a two - front war, splitting their forces between the European theatre against Nazi Germany and the Pacific War against the Japanese Empire, which was fighting in both Asia and the Pacific . </P>

During world war ii the united states was forced to fight a two-front war in