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Action
Offensives conducted on wide frontages—emphasizing few, rather than many, harmonious yet independent thrusts.
Evenness of advance maintained to protect flanks and provide artillery support as advance makes headway.
Reserves thrown in whenever attack held-up—against regions or points of strong resistance.
Reaction
Defense organized into depth of successive belts of fortified terrain.
Massed artillery and machine-gun fire designed to arrest and pin down attacker.
Counter-attack to win back lost ground.
Result
Stagnation and enormous attrition since advances made generally as expected along paths of hardened resistance because of dependence upon railroads and choice of tactics of trying to reduce strong points by massed firepower and infantry.