That month, Lieutenant General John Monash became commander of the Australian Corps, replacing William Birdwood. Following the German attack on the French around Aisne, the Allies began reorganising their defensive planning to negate the German assault techniques and to improve survivability of troops in forward areas. The German attack around the Aisne had demonstrated the vulnerability of garrisoning outposts too strongly, as heavy trench mortar bombardments had inflicted heavy casualties on the troops in the forward area, which had helped the Germans to break-in to the Allied position. It also demonstrated the need to maintain strong counterattacking forces in depth, with the ability to respond quickly to any assault, and to use manoeuvre to retake any ground lost. Machine gun positions were established behind the line, outside of the initial bombardment area, and efforts we made to improve the protection provided to troops by increasing the amount of dug-outs and establishing alternative firing positions for supporting artillery batteries. Troops in forward areas were to be consolidated into platoon strength positions to provide sufficient forces for a counter-attack, and further training was provided to perfect techniques such as gas drills and fire and movement in situations where only limited artillery support was available. Staff training was also increased to improve command and control.