On the night of 10 August in Washington, American Colonels Dean Rusk and Charles H. Bonesteel III were tasked with dividing the Korean Peninsula into Soviet and U.S. occupation zones and proposed the 38th parallel. This was incorporated into America's General Order No. 1 which responded to the Japanese surrender on 15 August. Explaining the choice of the 38th parallel, Rusk observed, "even though it was further north than could be realistically reached by U.S. forces, in the event of Soviet disagreement...we felt it important to include the capital of Korea in the area of responsibility of American troops". He noted that he was "faced with the scarcity of US forces immediately available, and time and space factors, which would make it difficult to reach very far north, before Soviet troops could enter the area". As Rusk's comments indicate, the Americans doubted whether the Soviet government would agree to this. Stalin, however, maintained his wartime policy of co-operation, and on 16 August the Red Army halted at the 38th parallel for three weeks to await the arrival of U.S. forces in the south.

What job were Colonels Dean Rusk and Charles H. Bonesteel III given?