60th (2/2nd London), 4th Australian and 5th Australian divisions in June and the 11th (Northern) Division on 3 July. The 55th (West Lancashire) and 56th (1/1st London) divisions were reassembled, a battalion of the Newfoundland Regiment and the South African Brigade joined in April, followed by a contingent of the Bermuda Volunteer Rifle Corps in July. Despite considerable debate among German staff officers, General Erich von Falkenhayn, the head of (OHL, the supreme command of the German Army) insisted on a tactic of rigid defence of the front line in 1916 and implied after the war that the psychology of German soldiers, shortage of manpower and lack of reserves made the policy inescapable, since the troops necessary to seal off breakthroughs did not exist. High losses incurred in holding ground by a policy of no retreat were preferable to higher losses, voluntary withdrawals and the effect of a belief that soldiers had discretion to avoid battle. When a more flexible policy was substituted later, discretion was still reserved to army commanders. Despite the certainty by mid-June of an Anglo-French attack on the Somme against the 2nd Army, Falkenhayn sent only four divisions, keeping eight in the western strategic reserve. No divisions were moved from the 6th Army, despite it holding a shorter line with divisions and three of the divisions in reserve being in the 6th Army area. The maintenance of the strength of the 6th Army at the expense of the 2nd Army on the Somme, indicated that Falkenhayn intended a counter-offensive against the British to be made closer to Arras north of the Somme front, once the British offensive had been shattered. Tactical developments French The offensives of 1915 showed that attacks would inevitably be slow and costly; on 8 January 1916, GQG issued (Instruction on Small Unit Offensive Operations) and on 26 January (Instruction on large Unit Offensive Operations). On 20 April, General Ferdinand Foch, commander of (GAN, Northern Army Group) issued (The GAN Commander's Instruction on Offensive Battle) an pamphlet on the stages and processes of an attack on enemy positions prepared in depth. The pamphlet was a substantial revision of , derived from (Purpose and Conditions of Comprehensive Offensive Action 16 April 1915), a manual compiled from analysis of the fighting in 1914, the basis of French offensive planning in 1915. Battle would now be methodical until the power of resistance of the defender was