In July 1914 Europe consisted of two opposing camps, Austria-Hungary and Germany (the Central Powers) and the Allies: France, Russia and Britain. Under established treaty agreements (the Triple Alliance and Triple Entente), each member was to help the other in the event of military threats from its rival camp. On 28 July, when Austria-Hungary declared war on Serbia, Russia agreed to Serbia’s request for support. Germany, although supportive of Austria-Hungary, was also determined to increase its military dominance. Austria-Hungary’s war plan was to concentrate on crushing the Serbs and protecting its borders from Russia. Germany’s plan was to advance through neutral Belgium and attack French forces near Paris. The Germans knew that the French planned to reclaim Alsace and Lorraine, taken in the Prussian war. Britain, distracted by internal problems, initially had no war plan, only feeling compelled to enter the war after Germany’s aggressive actions in neutral Belgium.