July 21st, 1915

- General Castlenau of the French Army Group of the Centre sends to Joffre his outline for the fall offensive in Champagne.  He proposes to have 2nd and 4th Armies undertake the main attack, with 5th Army (on the left) and 3rd Army (on the right) in supporting roles.  To ensure a 'particularly effective' artillery bombardment, Castlenau states that the operation will require ten days supply of munitions.  For the attack itself he envisions two phases: first, to rupture the German front and push the remnants back to a depth of twelve miles, which would provide reserve forces, in the second phase, sufficient room to maneouver to 'inflict a severe defeat on a significant part of the opposing forces on the Franco-Belgian front.'

- In southern Poland the German and Austro-Hungarian offensive continues.  West of the Vistula, Landwehr under the command of General Woyrsch punches a two kilometre hole in the Russian line at Zwolen this morning and push northward towards the Russian fortifications at Ivangorod, while 4th Landwehr Cavalry Brigade is sent east towards the bridges across the Vistula at Novo Alexandriya.  Further east attacks of the Austro-Hungarian 4th and German 11th Armies achieve only local successes, while the Army of the Bug occupies Hrubieszow on the right flank of the main advance.

- As their forces continue their offensives in Poland, the military leadership of Germany and Austria-Hungary give due consideration to the ultimate purpose of their actions on the Eastern Front.  Today Conrad sends a memorandum to Falkenhayn, copied to the the Austro-Hungarian Foreign Minister, urging that the military victories accomplished since May should be exploited to achieve a separate peace with Russia; in Conrad's phrase, a 'golden bridge' should be constructed that would allow the Russians to accept a reasonable peace.  Conrad's motive in forwarding the recommendation is partly revealed by a private letter written to General Artur von Bolfras today in which he writes that after peace with Russia, they 'could successfully deal with Italy.'  For the Austro-Hungarian chief of staff, the fight against Russia remains simply a means to an end, a necessary evil that must be finished before he can turn the full strength of the Austro-Hungarian army (such that it is) against the enemy who betrayed (in his eyes) the Dual Monarchy in August 1914.

- At 2am this morning Austro-Hungarian artillery launch a heavy bombardment on the Italian forces on the summit of Monte San Michelle, less than twelve hours after the latter captured the heights, and without time to adequately entrench the Italians suffer significant casualties.  Two hours later, fifteen Austro-Hungarian battalions launch a counterattack to retake San Michelle, and after several hours of hand-to-hand fighting the Italians fall back, yielding the only significant gain of the offensive on the Isonzo River launched on the 18th.  Even in the mountainous terrain of the Italian Front it is possible to gain ground, but it is even more difficult to hold against immediate counterattacks; it is harder to dig trenches in rock than dirt.