German scale of mobilization: central section of general staff connected to berlin post offices by telephone, telegraph, pneumatic tubes. 200 000 telegraph and 100 000 operators were waiting to contact the 106 infantry brigades: general staff railway section and 23 sub-offices control . Russia plan 19: focus on a-h, but promised french to launch offensives against a-h and. Germany d+15: attacks against east prussia with 800 000. France plan xvii: general joseph joffre, 3 armies attack into lorraine with elan still considered the primary concept, 1 army along the franco-belgian frontier, 1 army in reserve, no plans for belgium or british forces. War declarations: 28 july: a-h declares war on serbia, 1 aug: germany invades france. Germany declares war on russia: 3 aug: germany declares war on france, 4 aug: germany declares war on belguim. Britain declares war on germany: 6 aug: a-h declares war on russia. Serbia declares war on germany: 12 aug: france declares war on a-h.