Two-front war

In military terminology, a two-front war is a war 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.

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, 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.

During the Seven Years' War, the Kingdom of Great Britain invaded New France, creating a two front war with France.

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.

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