225 Mr S.M. Bruce, High Commissioner in London, to Mr R.G. Menzies, Prime Minister
Cablegram 460 LONDON, 14 September 1939, 7.41 p.m.
MOST IMMEDIATE FOR PRIME MINISTER MOST SECRET
Following is most confidential and every precaution must be taken to preserve its secrecy. Reference questionnaire my telegram number 441. 
I had long discussion with sub-committee of War Cabinet, Simon , Halifax , Chatfield , Hankey , Eden  last night.
Following is result.
(3) (Will an early success by Germany against Poland determine Mussolini  to come down on the side of those leaders in Italy who desire that Italy should come into the war taking the German side?) Hopeful view was taken of Italy's continued neutrality on grounds of increasing information as to hostility of Italian people to entering war on German side and that Mussolini would not risk discontent and possibly revolution that would follow war decision:
also that Mussolini as a realist would not desire a German victory, resulting in a Germany so powerful that Italy would be at her mercy. Even considered possible that as war progresses, Italy might come in on our side.
(2) (Is an early success by the Germans in Poland likely to influence the Turks to refrain from completing agreements with the United Kingdom and France and to adopt an attitude of strict neutrality?) View was that Turkey will sign although insisting on hard bargain, and in the event of Italy entering war or Roumania being attacked would take military action.
(4) (How far can the Spaniards' neutrality be relied on, particularly in view of the Ambassador at Rome communication of 8th September, see Stirling's cable?) 
View was that Spain will remain neutral and strong French opinion to this effect was quoted.
(5) (How serious is the danger of Japan's attempting to fish in troubled waters and how far would such a danger be offset by the fact that a move by Japan might lead to United States intervention?) Nothing further to add to views in Dominions Office telegram. 
With regard to Danubian and Balkan countries, view was that it will be possible for them to remain neutral and that they should was in our best interests.
I feel that the picture given above tends to be too optimistic and in discussion I put the arguments on other side but views I have indicated were adhered to.
(1) (Is it contemplated that any steps can be taken which would force the Germans to retain in the East forces beyond those necessary to contain Poland and to ensure the neutrality of Roumania?) Answer is no. Forces necessary difficult to estimate, probably fifteen to twenty divisions and relatively unimportant air force.
Position entirely altered should Germany decide to attack Roumania.
(13) and (7) (Is it estimated that serious operations between Germany and the Anglo-French forces would develop before the winter? If so, have the French and British sufficient divisions plus the necessary cooperation available to hold the Germans?) (Is it considered that the Maginot Line is impregnable, irrespective of number of German divisions available and the lessons the Polish campaign has taught us as to the power of a strong air force against ground troops and communications in interfering with reinforcements and supplies?) Not contemplated that major operations could develop in the winter. Maginot and Siegfried lines are regarded as impregnable.
Only possibility of an attack was through Holland and Belgium, but considered that it was unlikely that sufficient forces could be transferred in time and at present no German concentration reported on either frontier.
Assuming no major operation before the winter following points go forward to spring.
(6) (In view of the apparent probability that Germany will suffer a relatively small diminution of her man-power and equipment as the result of the Polish campaign, how many divisions is it contemplated that she could transfer to the Western Front?) Owing to uncertainties as to developments in Poland cannot be answered at present.
(11), (10) and (8) (How far is it contemplated that Anglo-French assistance could be given in relatively open warfare that would take place in Belgium?), (After such attack develops, how much resistance is it estimated could be offered to it by the Netherlands opening the dykes and flooding the country and by armed resistance and Belgium by armed resistance?) and (Assuming the Maginot Line on the German and French border is impregnable, is it considered probable that the Germans will attempt an attack through the Netherlands and/or Belgium?) In case of attack through Holland and Belgium, it was contemplated French and particularly British, who would be on the left, would reinforce the Belgians on a line Scheldt-Leige. Owing to Belgian neutrality and their refusal of discussions, difficult to make any preparations. Further attempt is now being made to obtain their agreement to staff talks. Could obtain no information as to the value of Dutch armed resistance but flooding of country would seriously embarrass the Germans.
(12) (Is immediate and extensive action being taken to strengthen the Maginot Line between France and Belgium from the Ardennes to the Coast?) No-but discussions are now proceeding between British and French.
(14) (How far would the British forces be sufficient to take such a reasonable proportion of the line of resistance to active German attack as to avoid dissatisfaction on the part of the French as to the share of the burden they were carrying?) Considered certain that ten divisions will be in France by spring and contemplated that at least twenty divisions within twelve months all fully equipped.
(16), (17) and (18) (With Italy in, would it be contemplated that any attack would be developed by the French on the French-Italian border?), (Conversely is it contemplated that any German-Italian attack would be developed against France?) and (How far would the necessity of reinforcing Egypt reduce the number of troops available for France?) Owing to view indicated above that Italy will remain neutral these were not discussed.
(19) (To what extent would our power to wage economic warfare be diminished by dominating position the Germans will hold in the East enabling them to exercise irresistible pressure on the Danubian countries including unrestricted river transport of supplies?) This is being exhaustively examined by the Ministry of Economic Warfare and I will advise you later.
Am still closely examining air position and much of the above may be modified as a result of such consideration.