148 Curtin to Churchill
Cablegram Johcu 62 (extracts) CANBERRA, [30 March 1943] 
IMMEDIATE MOST SECRET
With reference to Winch No. 6 , I was about to cable you that Dr. Evatt will be leaving for Washington and London by air on 5th April and that he will be able to support our case in person and by reference to documents. I would thank you for the expression of your desire to discuss with him the vitally important matters which I have raised with you.
2. There are, however, certain brief comments I would like to make on the reasons that have been stated by the British Chiefs of Staff for the views expressed by them.
[Paragraphs 3-8 were essentially similar to paragraphs 2-6 of the cablegram published as Document 146.]
9. With reference to 3 (a) and (b), our experience of the Japanese has indicated a definite tendency of your Advisers to under-rate them as a foe. This under-estimation is not held by the Commanders in the South-West Pacific Area who have fought them, and we do not feel that sufficient weight is being attached to their views. The observations of the British Chiefs of Staff on the Japanese air force in these sub-paragraphs causes an uneasiness when we recall the following advice given in April, 1941:-
'The majority of the 450 shore-based aircraft which the Japanese can marshal against us are of obsolete types, and, as we have said, we have no reason to believe that Japanese standards are even comparable with those of the Italians.' 
We have learnt from bitter experience that this was a gross underestimation of Japanese air power.
10. In regard to 3 (c), I understand that the strength of United States land-based aircraft in the South-West Pacific Area is approximately 750. The R.A.A.F. has some 700 modern aircraft and roughly 400 aircraft of obsolescent types, such as Wirraways and Hudsons, which are to be replaced.
11. I am very disturbed at the delay in delivery of aircraft from the United States. We were told last August that 397 aircraft were to be made available to the R.A.A.F. from United States production, under the plan then approved by the Combined Chiefs of Staff for expansion to 30 squadrons.  Deliveries were to be spread over a period of about 8 months, so that we expected to have our quota of 397 aircraft by the end of March, 1943. The present position is that only 160 aircraft have been shipped.  This delay is most disappointing and is seriously affecting the operational efficiency of the R.A.A.F. As a result, it has been necessary completely to revise the development programme. Air crews which had been trained, and supporting units which had been formed and equipped in anticipation of receiving these aircraft allocations, had to be absorbed in other directions, and, as you will well appreciate, this has acted to the detriment of the planned development programme.
12. Of the total United States and R.A.A.F. strength in the South- West Pacific Area, there are at present only about 650 aircraft in a serviceable condition. The delivery of aircraft spares and equipment from the United States and also, to a lesser extent, from United Kingdom production is disappointing and an acute stage will shortly be reached in respect of the maintenance of certain of our squadrons, notably Kittyhawks, unless something is done to remedy the situation. Dr. Evatt will be in a position to discuss these aspects also.
13. In conclusion, I would refer to the following observations by me in my most recent review to Parliament :-
'As to the prospects for the future and the duration of the struggle, I would remind every Australian of the basis on which Mr. Churchill reached his conclusion that there is nothing to justify an optimistic view that the end is in sight. He referred to an enslaved Europe with all its resources at Germany's disposal. He pointed out that the Eighth Army in Africa had defeated only a few divisions of Germany's great army. He mentioned that the U-boat menace is not diminishing, but growing.
So much for the task of defeating Germany, but what about Japan? She, too, is master of vast territories with large populations and vital resources for the waging of war. Though she has suffered certain naval and air losses, her strength is still great. Like Germany, Japan prepared for this war for years and did not strike until she was ready to do so and considered the situation favourable for success. It should not be overlooked that we are fighting her at places vital to our own security and far removed from her own final ramparts of defence.'
[14.] The minimum for which we ask is not the establishment of a bare air superiority over the Japanese, but the provision of such air power as will enable the Forces in the South-West Pacific Area to prevent the consolidation of the Japanese in their positions to the North of Australia and so render reasonably feasible the task of ultimately defeating them when the war in Europe ends. We still hope that the decisions of the Casablanca Conference and the reference to retaining the initiative against Japan contemplate this.