The first of these large anti-Partisan offensives was "Fall Weiss", also known as the Battle of Neretva. The Chetniks participated with a significant, 20,000-strong, force providing assistance to the German and Italian encirclement from the east (the far bank of the river Neretva). However, Tito's Partisans managed to break through the encirclement, cross the river, and engage the Chetniks. The conflict resulted in a near-total Partisan victory, after which the Chetniks were almost entirely incapacitated in the area west of the Drina river. The Partisans continued on, and later again escaped the Germans in the Battle of Sutjeska. In the meantime, the Allies stopped planning an invasion of the Balkans and finally rescinded their support for the Chetniks and instead supplied the Partisans. At the Teheran Conference of 1943 and the Yalta Conference of 1945, Soviet leader Joseph Stalin and British Prime Minister Winston Churchill decided to split their influence in Yugoslavia in half.