Assumptions Regarding the Japanese

1)      That the Japanese will continue the war to the utmost extent of their capabilities and will prepare to defend the main islands of JAPAN with every means available to them.  That operations in this area will be opposed not only by the available organized military forces of the Empire, but also by a fanatically hostile population.

2)      That approximately three (3) hostile divisions will be disposed in Southern KYUSHU and an additional three (3) in Northern KYUSHU at initiation of the OLYMPIC operation.

3)      That total hostile forces committed against KYUSHU operations will not exceed eight (8) to ten (10) divisions and that this level will be speedily attained.

4)      That approximately twenty-one (21) hostile divisions, including depot divisions, will be on HONSHU at the initiation of that operation and that fourteen (14) of these divisions may be employed in the KANTO PLAIN area.

5)      That the enemy may withdraw his land-based air forces to the Asiatic Mainland for protection from our neutralizing attacks.  That under such circumstances he can possibly amass from 2,000 to 2,500 planes in that area by exercise of rigid economy, and that this force can operate against KYUSHU landings by staging through homeland fields.

6)      That the attrition caused by our continued land-based and carrier-based air preparation and support, and by our destruction of aircraft manufacturing and maintenance facilities, will reduce this hostile capability for air action against our landings to suicide attacks of uncertain proportions at an early phase of the operations.

7)      That hostile fleet elements will be forced to withdraw to the YELLOW SEA or Western SEA OF JAPAN.  That the enemy will maintain the capability of a suicide attack against KYUSHU landings with the approximate strength of a typical carrier task group.  That his remaining submarines and large numbers of small suicide craft will oppose our landings and that mines will be used in large numbers.

8)      That hostile sea communications across the JAPAN SEA, while relatively unimpaired prior to the KYUSHU landings, will be progressively and rapidly restricted to complete interdiction by the time air is operating from HONSHU.

9)      That during continuation of Russian neutrality, the production capacity of hostile industries and raw material sources in MANCHURIA, North CHINA, and KOREA will remain relatively unimpaired.

10)  That hostile logistic position will permit determined defense in areas of projected operations by hostile ground forces enumerated in (3) and (4) above.