Extract 2 WHITEHALL GARDENS, LONDON, 21 June 1937
Sir Thomas Inskip, Minister for Co-ordination of Defence (in the Chair) Malcolm MacDonald, Secretary of State for Dominion Affairs Admiral of the Fleet Lord Chatfield, First Sea Lord and Chief of Naval Staff Sir Archdale Parkhill, Minister for Defence, Australia Marshal of the Royal Air Force Sir Edward Ellington, Chief of the Air Staff Field Marshal Sit Cyril J. Deverell, Chief of the Imperial General Staff
Sir Edward Harding, Permanent Under-Secretary of State for Dominion Affairs N. K. Brodribb, Deputy Controller, Munitions Supply, Australia F. G. Shedden, First Assistant Secretary and Civil Member of Defence Committee, Department of Defence, Australia Vice Admiral Sir Reginald G. H. Hendersen, Third Sea Lord and Controller Vice Admiral Sir William M. James, Deputy Chief of Naval Staff Colonel Sir M. P. A. Hankey (Secretary) Colonel H. L. Ismay (Deputy Secretary) Major V. Dykes (Assistant Secretary) Major L. C. Hollis (Assistant Secretary)
The Sub-committee had under consideration a Report by the Chiefs of Staff on the detailed questions raised by the Australian Delegation (Paper No. C.O.S. 595)  and observations thereon by the Australian Delegation (Paper No. C.O.S. 598). 
SINGAPORE: PERIOD BEFORE RFLIEF
SIR THOMAS INSKIP invited the Sub-committee's attention to the first question raised by the Australian Delegation as set out in page 1 of Paper No. C.O.S. 598, in which advice was asked as to the time for which it was estimated the Singapore base would resist capture at the present stage of its defences and the period for which it would ultimately be able to hold out when the Defences were complete. This question originated from paragraph 24 of the Chiefs of Staff Report (Paper No. C.O.S. 595) which read as follows:-
'To take a probable situation in the European theatre, our Naval forces may be operating in strength in the Atlantic, considerably dispersed. French battle cruisers may be assisting in these operations while a proportion of our heavy ships may be assisting with French-African convoys. If in these circumstances we have to deal with Japan, a very considerable period may elapse before the progress of our operations against Germany and the redistribution of our forces permit of a fleet arriving in the Far East.'
It would be noted that the above passage referred to a situation when we were already engaged in war with Germany before war with Japan had broken out. The situation implicit in the question (now put forward) was that Singapore was a beleaguered fortress and would be called upon to resist prolonged attack without the prospect of relief by our fleet. This was not the realistic picture, since while the land communications remained, Singapore would not be beleaguered. The Committee of Imperial Defence were now engaged upon the investigation of the reserves of stores which should be maintained at Singapore. Consequently the answer to the Australian question depended upon a number of unknown factors which had not yet been fully assessed. In these circumstances it was impossible for the Chiefs of Staff to give categorical answers to the question now put forward by the Australian Delegation.
SIR ARCHDALE PARKHILL said that it was to be assumed that the Japanese would try to render Singapore useless as a base. Could the Chiefs of Staff estimate the time which the fortress might hold out in the face of a full scale frontal attack by the Japanese, 'assuming that the latter aimed at reducing the fortress in the shortest possible time? SIR THOMAS INSKIP, said that our policy was to render Singapore secure from military attack, using the term military in the broadest sense.
SIR ARCHDALE PARKHILL said that it would be a great help in framing the Australian defence programme if the Chiefs of Staff could state whether the defences now in course of installation in the fortress would enable it to hold out for say three or six months.
SIR CYRIL DEVERELL observed that even if Singapore were entirely beleaguered, it could hold out for much longer than the actual period for which reserves of stores were maintained. History had shown that a besieged fortress was almost invariably able to hold out longer than had been anticipated.
SIR ARCHDALE PARKHILL said that, having in mind the delay which might occur before the fleet would sail to the East owing to European implications or other factors, if Australia could be certain that Singapore would hold out, this would have an important effect upon the Australian defence policy. If there was a danger of Singapore falling within 70 days, then Australia might as well abandon the programme for increasing her navy and concentrate all her defence resources on her army and air force.
SIR MAURICE HANKEY said that our whole defence policy in the Far East was directed towards ensuring that Singapore would hold out.
With this object in view a huge scheme of defence was in course of being carried through, including the provision of 15-inch guns.
The importance of Singapore had been emphasised in the Far East Appreciation prepared by the Chiefs of Staff, in which the difficulties attending an attack by the Japanese on Singapore had been set out in detail. His Majesty's Government in the United Kingdom were basing the whole of their plans on the assumption that Singapore would not fall; and it would, he suggested, be consistent for His Majesty's Government in Australia to proceed upon the same assumption.
SIR EDWARD ELLINGTON said that it was not possible to make an accurate forecast of the scale of air attack to which Singapore might be subjected, or as to the degree of success which such attack would attain. Heavy and sustained air attacks could not be maintained on the fortress unless and until shore-bases had been established within air range. This would entail prolonged operations.
LORD CHATFIELD said that our policy was to make sure, in our own interests, that Singapore should not fall. The measures we should take to make the fortress impregnable were a matter for careful calculation since in addition to the provision of active defences (e.g. guns, garrison and air forces) it was necessary to assess other factors such as the reserves of munitions, food stocks to be maintained and so forth. It would be a reasonably safe assumption to make that Singapore would not fall before the arrival of the fleet.
SIR THOMAS INSKIP remarked that the investigation by the Committee of Imperial Defence of reserves of stores, to which he had already referred, presupposed that the defences would be strong enough to resist any scale of attack which the Japanese could be expected to launch against them.
SIR MAURICE HANKEY observed that it would always be impossible to give a precise and comprehensive forecast of everything which might happen in war.
SIR ARCHDALE PARKHILL said that in view of the explanations that had been given, he felt he could assume that the defences of Singapore were such that the fortress could resist frontal attack by the Japanese for a considerable time. While it might be going too far to say that the fortress was impregnable for an indefinite period, it would be true to say that it was so strong that it would be able to resist attack prior to the arrival of the fleet.
If the above assumptions were not tenable, Australia would be left in the dark as to their defence policy.
LORD CHATFIELD said that the whole basis of our policy for the last ten years had been to make Singapore so strong that the Japanese would not risk attacking it and thereby subjecting their heavy ships to damage by 15-inch gunfire.
SIR ARCHDALE PARKHILL said that his reason for pressing the Chiefs of Staff on this point was that the section of opinion in Australia which advocated the concentration of defence expenditure on the Army and Air Force instead of on the Navy explored two main arguments: the first was that the British Fleet would not be sent to the Far East at all; and the second: that even if it were sent Singapore would not be strong enough to resist capture before its arrival. The first argument had been disposed of by the Chiefs of Staff Appreciation, but an assurance was required that the second argument was also groundless.
SIR THOMAS INSKIP thought that the necessary assurance had, in fact, already emerged from the discussion.
LORD CHATFIELD added as a further point, that so long as the British Fleet was in being the Japanese would always have the fear at the back of their minds that it would arrive in the Far East.
It was therefore unlikely that they would embark on prolonged operations against Singapore-with the attendant risk of damage to their capital ships-so long as there was a chance that they might have to break off these operations, and engage the British Fleet.
If, on the other hand, our fleet had been sunk (e.g. in European waters) then the Japanese would be in a position to stage operations to reduce Singapore at their leisure. To sum up, Singapore could be regarded as a first-class insurance for the security of Australia. If, however, he were to be asked whether Singapore was 100 per cent. secure or only 99.1 per cent. it would be impossible to give a categorical answer.
SIR ARCHDALE PARKHILL enquired whether the fortress could be regarded as being 75 per cent. secure.
SIR CYRIL DEVERELL said that all our plans were based upon the fortress holding out, and it would therefore be reasonable to assume a very much higher percentage of security.
SIR ARCHDALE PARKHILL expressed himself as satisfied with the assurance given him by the Sub-committee.
SINGAPORE: DATE OF, COMPLETION OF DEFENCES
SIR THOMAS INSKIP, referring to the question asked at the bottom of the first page of Paper No. C.O.S. 598, regarding the year in which it was hoped to complete the defences of Singapore, said that the answer was to be found in paragraph 314 of the Chiefs of Staff Review of the Far East (Paper No. C.O.S. 590).