1) France implemented Plan XVII at the start of WWI to launch an offensive into Alsace-Lorraine, but the German defense was stronger than expected. The German Schlieffen Plan aimed to defeat France quickly and transfer troops to the Eastern Front against Russia. 2) Germany's Schlieffen Plan sought to avoid a two-front war by defeating France first before fighting Russia, but the plan failed when France halted the German advance at the First Battle of the Marne. 3) Austria-Hungary had Plan B to deal with the Balkan states and Plan R to defend against Russia in case of war with Serbia, revealing its intent to respond aggressively to the Sarajevo Crisis.