gap between the German armies as they closed on Paris. The French and British exploited this gap to halt the German advance east of Paris at the First Battle of the Marne from 5to 12 September and push the German forces back some . In 1911, the Russian Stavka had agreed with the French to attack Germany within fifteen days of mobilisation, ten days before the Germans had anticipated, although it meant the two Russian armies that entered East Prussia on 17 August did so without many of their support elements. Although the Russian Second Army was effectively destroyed at the Battle of Tannenberg on 26–30 August, their advance caused the Germans to re-route their 8th Field Army from France to East Prussia, a factor in Allied victory on the Marne. By the end of 1914, German troops held strong defensive positions inside France, controlled the bulk of France's domestic coalfields and had inflicted 230,000 more casualties than it lost itself. However, communications problems and questionable command decisions cost Germany the chance of a decisive outcome, while it had failed to achieve the primary objective of avoiding a long, two-front war. As was apparent to a number of German leaders, this amounted to a strategic defeat; shortly after the Marne, Crown Prince Wilhelm told an American reporter; "We have lost the war. It will go on for a long time but lost it is already." Asia and the Pacific On 30 August 1914, New Zealand occupied German Samoa, now the independent state of Samoa. On 11 September, the Australian Naval and Military Expeditionary Force landed on the island of New Britain, then part of German New Guinea. On 28 October, the German cruiser sank the Russian cruiser Zhemchug in the Battle of Penang. Japan declared war on Germany prior to seizing territories in the Pacific which later became the South Seas Mandate, as well as German Treaty ports on the Chinese Shandong peninsula at Tsingtao. After Vienna refused to withdraw its cruiser from Tsingtao, Japan declared war on Austria-Hungary as well, and the ship was sunk at Tsingtao in November 1914. Within a few months, Allied forces had seized all German territories in the Pacific, leaving only isolated commerce raiders and a few holdouts in New Guinea. African campaigns Some of the first clashes of the war involved British, French, and German colonial forces in Africa. On 6–7 August, French