J. C. S. Files

No. 599
Memorandum by the United States Chiefs of Staff 1
top secret
C. C. S. 880/4

Development of Operations in the Pacific

In conformity with the over-all objective to bring about the unconditional surrender of Japan at the earliest possible date, the United States Chiefs of Staff have adopted the following concept of operations for the main effort in the Pacific:—
From bases in Okinawa, Iwo Jima, Marianas, and the Philippines to intensify the blockade and air bombardment of Japan in order to create a situation favorable to:
An assault on Kyushu for the purpose of further reducing Japanese capabilities by containing and destroying major enemy forces and further intensifying the blockade and air bombardment in order to establish a tactical condition favorable to:
The decisive invasion of the industrial heart of Japan through the Tokyo Plain.
We have curtailed our projected expansion in the Ryukyus by deferring indefinitely the seizure of Miyako Jima and Kikai Jima. Using the resources originally provided for Miyako and Kikai, we have accelerated the development of Okinawa. By doing this, a greater weight of effort will more promptly be brought to bear against Japan and the risk of becoming involved in operations which might delay the seizure of southern Kyushu is avoided.
In furtherance of the accomplishment of the over-all objectives, we have directed:—
The invasion of Kyushu, target date 1 November 1945.
The continuation of operations for securing and maintaining control of sea communications to and in the Western Pacific as are required for the accomplishment of the over-all objective.
The defeat of the remaining Japanese in the Philippines by such operations as can be executed without prejudice to the over-all objective.
The seizure of Balikpapan, target date 1 July 1945.
The continuance of strategic air operations to support the accomplishment of the over-all objective.
Planning and preparation for the campaign in Japan subsequent to the invasion of Kyushu is continuing on the basis of meeting a target date of 1 March 1946 for the invasion of the Tokyo Plain. This planning is premised on the belief that defeat of the enemy’s armed forces in the Japanese homeland is a prerequisite to unconditional surrender, and that such a defeat will establish the optimum prospect of capitulation by Japanese forces outside the main Japanese islands. We recognize the possibility also that our success in the main islands may not obviate the necessity of defeating Japanese forces elsewhere; decision as to steps to be taken in this eventuality must await further developments.
We are keeping under continuing review the possibility of capitalizing at small cost, without delaying the supreme operations, upon Japanese military deterioration and withdrawals in the China Theater.
We have directed the preparation of plans for the following:—
Keeping open a sea route to Russian Pacific ports.
Operations to effect an entry into Japan proper for occupational purposes in order to take immediate advantage of favorable circumstances such as a sudden enemy collapse or surrender.
  1. Noted by the Combined Chiefs of Staff at their 193d Meeting, July 16. See vol. ii, p. 38. Cf. appendix A to document No. 1381, printed in vol. ii .