A flank is the extreme left or right edge of a military formation, used throughout military history in differing forms, techniques and cultures. In military tactics, a flanking manoeuvre is a movement of an armed force around a flank to achieve an advantageous position over an enemy. Flanking is useful because a force's offensive power is concentrated in its front. Therefore, to circumvent a force's front and attack a flank is to concentrate offense in the area when the enemy is least able to reciprocate.
Flanking can also occur at the operational and strategic levels of warfare. On an operational level army commanders may attempt to flank and wrong foot entire enemy armies, rather than just be content with doing so at a tactical battalion or brigade level. The most infamous example of such an attempt is the modified Schlieffen Plan utilized by the Germans during the opening stages of the First World War; this was an attempt to avoid facing the French armies head on, but instead flank them by swinging through neutral Belgium. Flank attacks on the strategic level are seen when a nation or group of nations surround and attack an enemy from two or more directions, such as the Allies surrounding Nazi Germany in World War II. In these cases, the flanked country usually has to fight on two fronts at once, placing it at a disadvantage.[1]