The Indirect approach is a military strategy described and chronicled by B. H. Liddell Hart after World War I.
It was an attempt to find a solution to the problem of high casualty rates in conflict zones with high force to space ratios, such as the Western Front on which he served.
[1] "Throughout the ages, effective results in war have rarely been attained unless the approach has had such indirectness as to ensure the opponent’s unreadiness to meet it… In strategy, the longest way round is often the shortest way home.”[2] A direct approach to the object exhausts the attacker and hardens the resistance by compression, where as an indirect approach loosens the defender's hold by upsetting his balance".
In battle, there are not more than two methods of attack – the direct and the indirect; yet these two in combination give rise to an endless series of maneuvers.
It was in reality an attempt to create a doctrine for the remobilization of warfare after the costly attrition of the strategic stalemate of the First World War.