Cablegram E152 WASHINGTON, 12 June 1943, 5.09 a.m.
The following is an appreciation of the probable position in the
South West Pacific. It was given to me in order to indicate the
strength of the case against any further expansion of the R.A.A.F.
The figures therefore do not include any increase in R.A.A.F.
squadrons above 45. I do not think that it is necessary to have
our own Chiefs of Staff prepare for me any considered answer but
the document should be very useful especially to Shedden.
(1) Our agreed strategy aims at firstly defeating Germany and then
turning our whole efforts against Japan. Until Germany is defeated
we are exerting unremitting pressure on Japan with all the forces
we can spare. The objects of this offensive are to wear down
Japanese sea and air power and cause shipping losses, while
preventing the Japanese from consolidating their positions
sufficiently to enable them to stage an offensive themselves. At
the same time we aim at the attainment of positions from which to
menace Japanese sea communications.
(2) The operations in the Solomons and New Guinea which will
culminate in seizure of Rabaul have forced the Japanese on the
defensive. Attacks by aircraft and submarines continue to keep
enemy shipping losses above their rate of building. Our present
operations are achieving the objects of our strategy and, as our
forces will steadily increase, they should continue to do so.
(3) Limitations imposed by shipping. The margin of Japanese
shipping available for operations, after allowing for trade and
overseas maintenance commitments, has fallen to 600,000 and
continues to fall. Additional tonnage might be found from trade
for new operations without immediately serious effects on Japan's
economic position. Since, however, her shipbuilding cannot keep up
with the present rate of sinkings and since she must be aware of
growing Allied ability to increase that rate, she cannot afford to
incur serious losses inherent in any large scale seaborne assault
nor can she risk additional commitments entailed in further
extending her sea communications.
(4) Japanese Intentions
The reversals at Guadalcanal and in New Guinea have brought home
to the Japanese the risks involved in seaborne expeditions in the
face of land based aircraft. Japan is now faced with increasing
Allied naval, land and air forces in all areas from India to the
Aleutian Islands and the absolute limitations of her shipping
position are never likely to increase. In these circumstances her
strategy must be fundamentally defensive and be aimed at making
her existing conquests as impregnable as possible.
FORCES REQUIRED TO IMPLEMENT OUR STRATEGY
 Naval. Our strength in the South West Pacific is only just
equal to that of the Japanese but it is improbable that the latter
will increase materially their strength in this area. Not only
[is] America's threat in the Aleutian Islands growing in strength
but above all the stronger the American fleet becomes the greater
will be the Japanese anxiety for the defence of their home waters.
Allied fleets engaged against Japanese will increase, firstly due
to the United States new construction and secondly by the possible
release of British ships when Italy has been finally eliminated.
(6) Land Forces
Discounting Sumatra  Islands there is a maximum of 200,000
troops in deployment over a lateral distance of 3,000 miles in the
South and South-West Pacific Areas. It is probable that only 9 out
of the 13 divisions forming Japan's strategic reserve could be
made available for these areas.
Even discounting shipping losses which might be heavy, previous
experience indicates that it would take 9 months to concentrate in
the South West Pacific these 9 divisions.
Against this there are the equivalent of 11 Allied divisions in
Australia and 3 and 2/3rds divisions in New Guinea. There are some
11 equivalent divisions in the South Pacific Area. Five Australian
divisions are being trained in jungle warfare and 2 further
American divisions are being sent to reinforce the South West
Pacific during the next 5 months. There is thus a marked
superiority in Allied strengths and there should be sufficient
land forces for the capture of Rabaul and a subsequent advance on
Truk, apart from the security of our own bases.
(7) Air Forces
Although the Japanese have numerous and well distributed airfields
they cannot make available in the South-West Pacific Area
(excluding the Philippines) more than 700 land based and 150 to
200 carrier borne aircraft. Owing to their preponderant defensive
commitments from Java to Gilbert Islands, the Japanese could not
spare more than 200 of these land based aircraft to attempt any
Japanese air forces in the South West Pacific are only maintained
at their present level with difficulty and owing to the high rate
of wastage being incurred by Japanese in excess of balancing or
exceeding their production there is little likelihood of their
increasing. Even excluding air forces in the South Pacific the
Allied strength guarding Australia and in the South West Pacific
(not including transport aircraft) is already considerably in
excess of the total Japanese strength there and by the end of the
year will be nearly three times as great.
(1) The Japanese dispositions in the South and South West Pacific
are essentially defensive.
(2) So long as our present pressure on the enemy in New Guinea-
Solomons area continues, there will be no threat to Australia from
(3) In order to mount an attack from the north or north-west the
enemy could not concentrate a portion of his strategic reserve
estimated at 9 divisions available for this area at a greater rate
than 1 division per month. Even if he took this step the enemy
could not risk shipping losses nor accept added maintenance
commitments inherent in launching any further large scale
(4) Allied land forces are sufficient not only for the defence of
Australia but to continue with the plans of limited offensive
(5) To-day Allied air forces in the South West Pacific are
considerably more than those of the Japanese and by the end of the
year they should approximate 3 times as great.
(6) Though Allied naval strength in the Australian area has not
been preponderant over the Japanese it is sufficient, in
conjunction with shore based aircraft, not only for the defence of
Australia but for its part in our present offensive operations. It
will be increased considerably by the new American construction
throughout the year.
SHORE BASED AIR FORCES IN THE SOUTH-WEST PACIFIC AREA (NOT
INCLUDING THE PHILIPPINES)
JAPAN-NOW AND IN DECEMBER 1943
Area Fighters Bombers (a) Other Total Transport
Operational operational aircraft
Timor 111 109 39 259 -
Solomons 201 178 62 441 -
Totals- 312 287 101 700 -
R.A.A.F. 235 139 (b)86 (c)460 -
United States 286 283 82 651 135
Totals - 521 422 168 1,111 135
UNITED NATIONS-DECEMBER 1943
R.A.A.F. (d)312 318 198 828 45
United States 474 486 251 1,211 234
Totals- 786 804 449 2,039 279
(The following are notes)
(a) Includes P.R.U.-G.R.-A.C. -special [sic] and flying boats.
(b) Includes Torpedo bombers.
(c) Does not include G.P.  Wirraways still employed in
(d) These figures have been checked with the R.A.A.F. Mission in
Washington. They represent a reasonable estimate based on current