Your telegram M.93 : Commonwealth Government has given full consideration to your proposal for declaration by United Kingdom Government concerning Netherlands East Indies.
We are strongly impressed, however, by the objection that the absence of a corresponding and simultaneous declaration by United States Government might in present circumstances do real harm in that it might be held to indicate that no political agreement between United Kingdom and United States and the Netherlands had been reached or that the United States was not prepared to interfere with Japan's further southward move. From all information available we take it as a fact that such a declaration would not be forthcoming from United States Government at present.
Further, in his conversation while in Australia, Netherlands Foreign Minister let it appear that he did not in fact expect any open declaration from the United Kingdom regarding assistance to the Netherlands East Indies as he knew that the United Kingdom Government, in the light of European events, might reasonably be opposed to entering into new public commitments. Dr. Van Kleffens appears, however, fully satisfied that, irrespective of any prior commitments, the British Commonwealth in the event of an attack on the Netherlands East Indies would regard it as an attack on its own vital interests and would intervene automatically.
For these reasons Commonwealth Government feels that on the whole no useful purpose would be served by an open declaration at the present time, especially in view of general military situation.
At the same time, it is considered that a certain value would attach to a private assurance to the Netherlands Government in the same sense as that proposed for the public declaration. Dr. Van Kleffens in discussion here gave the impression of being quite definite that the Netherlands East Indies would fight if attacked and if necessary would fight alone. This impression is borne out by the public statements made by Van Kleffens while in Australia and in Netherlands East Indies. Further the stage reached in staff conversations in Singapore would appear to render it desirable that plans drawn up should now be based on clear political understanding. This is a point noted in paragraph 2 of your telegram under reference.
Commonwealth Government therefore for its part would welcome and endorse private assurance to the Netherlands Government, in lieu of proposed open declaration, to the effect that Netherlands East Indies in resistance to an attack on its territories could count on active assistance of British Commonwealth. Actual terms and extent of such assurance would naturally be linked with agreed strategical basis of Singapore conversations. Commonwealth Government would hope that it would be possible to obtain corresponding private assurance from the United States and suggests that an approach to this end might be made in Washington.
If it appeared unlikely however that the United States would agree, we would not for that reason wish United Kingdom declaration to be unduly delayed.