Two - front war In military terminology , a two - front war is one in which fighting takes place on two geographically separate fronts . It is usually executed by two or more separate forces simultaneously or nearly simultaneously , in the hope that their opponent will be forced to split their fighting force to deal with both threats , therefore reducing their odds of success . Where one of the contending forces is surrounded , the fronts are called interior lines . Examples . Ancient times . One of the earliest examples of a two - front war occurred in the third century BC , when the Roman Republic fought the First Macedonian War contemporaneously with the Second Punic War against Carthage . Also , after the consolidation of the Empire ' s frontier in the reign of Augustus , the Roman forces had to contend with multiple enemies in its frontiers , in the Rhine , the Danube and Mesopotamia , with various examples of emperors ( such as Septimius Severus and Aurelian ) who marched their armies from one side of the Empire to another to face them . In the later period , after the collapse of the Western Roman Empire , the surviving part , the Byzantine Empire had to face invaders coming from both west and east and simultaneously trying to preserve its territories in Italy . Napoleonic Wars . 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 . World War I . 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 , until the Bolshevik Revolution of 1917 took Russia out of the war . 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 . World War II . Perhaps the most famous example of a two - front war was the European theatre during World War II , when Hitler ' s Nazi Germany had to deal with the Western Allies on the west and the Soviet Union to the east . The Germans were unable to repel either of the two front ' s advances 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 due to 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 . 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 Japan . Japan too was fighting in both Asia and the Pacific . The Axis Powers had the opportunity to force the Soviet Union into a two - front war by means of a Japanese attack on the Soviet Far East , but the Japanese declined to do so , due to their defeats in the Soviet – Japanese border conflicts . While Germany and the United States remained respective threats , the Soviets and Japanese did not fight each another until the August 9 Soviet - Japanese War ( 1945 ) , three months after the surrender of Germany . In the case of the United States , the Pacific theatre was primarily a naval and air effort despite losing ships during the 1941 Pearl Harbor Attack while ground forces were used in Europe . Israeli - Arab Wars . In the 1948 Israeli - Arab War , the Israelis fought the Egypt ians to the south and the Jordanians and Syria in the east and north . Israel again fought two - front wars in the Six - Day War of 1967 and the Yom Kippur War of 1973 . Cold War . A major rationale for the American 600 - ship Navy plan in the 1980s was to threaten the Soviet Union with a two - front war ( in Europe and the Pacific Ocean ) in the event of hostilities . Metaphorically . Additionally , the term is often used metaphorically . An example is when a moderate politician faces political " attacks " from those to his left and those to his right .