As the Axis powers of Germany, Italy, and Japan cemented their joint military alliance by mutually declaring war against the United States by December 11, 1941, the Japanese proposed a clear territorial arrangement with the two main European Axis powers concerning the Asian continent. On December 15 they presented the Germans with a drafted military convention that would delimit the continent of Asia into two separate "operational spheres" (zones of military responsibility) by a dividing line along the 70th meridian east longitude, going southwards through the Ob River's Arctic estuary, southwards to just east of Khost in Afghanistan and heading into the Indian Ocean just west of Rajkot in India, to split the Lebensraum land holdings of Germany and the similar spazio vitale areas of Italy