(Due to arrive Canberra 15.3.29)
My Dear P.M.,
I think the proposal in the attached letter regarding C.I.D.
papers will meet the case.  I have had some signs that the Defence Department think that I am usurping some privilege of theirs by my position in the C.I.D. Office and by seeing and sending out through you copies of all C.I.D. papers that they seem to think affect them exclusively. They appear to resent the fact that I am the channel (through you) through which these papers reach them and that they are not available to their Service Liaison Officers here.
I mention this fact-not that it disturbs me a great deal-in order that you may be aware of the possibility of their trying to alter the present arrangement at this end. Personally, I think-and without trying to forward any ends of my own-that any alteration of the present scheme would not be an improvement. We are liable to lose more than we gain by any attempted change.
I think that the origin of their discontent lies in the fact that I was able to send you information which enabled you to postpone the 'modernisation' of our coast defences. I also hear echoes of criticism that I am biased in favour of the air. Both these criticisms annoy me a little. Firstly, I could not have advised you other than I did with regard to coast defence without gross dereliction of my duty to you. Secondly, I have gone through all my letters and notes to you on the question of the share that the Air should take in coast and other defence, and I am still of the opinion that I have always maintained a reasonable attitude in the matter. I have shown Hankey the bulk of my letters on the subject and he thinks I have maintained the balance.
I am, Yours sincerely, R.G. CASEY