I have read the opinion of the Solicitor General dated 20.5.1929,⁽¹⁾ and I agree in his view that the defence power extends sufficiently far to make it possible for the Commonwealth Parliament to make laws dealing with Category I, Category III, and Category II so far as articles whose primary use was for warlike purposes, are concerned.

The opinion of the Solicitor General suggests that the defence power does not extend to control all articles capable of use for military purposes whose primary use is not for such purposes.

The Solicitor General also considers that the defence power may not cover legislation of the character desired dealing with aircraft, assembled or dismantled, and aircraft engines.

I think that there is room for doubt as to these matters and I agree that the law has not been sufficiently clearly declared to make it possible to give an absolute opinion with respect to the matters particularly mentioned. The preliminary draft convention, however, deals with all the subject matter mentioned in it from the point of view of warlike operations. The essence of the convention is that the manufacture of articles which are either necessarily of a warlike character or of such a character that they may be readily used for warlike, purposes should be subject to Government licence. (See Article 3).

In my opinion if the Commonwealth Parliament were by legislation to approve the convention the legislation would be legislation with respect to defence. All the matters, including aircraft and other ambiguous articles, would be dealt with only in relation to and for the purposes of obtaining information and gaining control in regard to possible use in warlike operation.

I am, therefore, of opinion that the subject matter of the convention, viewed as it must be in direct relation to the provisions of the convention itself, is within the defence power of the Commonwealth.

The Commonwealth Parliament has power to legislate with respect to external affairs. The extent of this power has not been defined though the judgment of Higgins J. in Roche v. Kronheimer, 29 C.L.R., (1921) at page 329, contains some interesting observations upon the subject.

Control of such matters as the manufacture, export, etc. of warlike material is one of the most natural and necessary functions which a State may be called upon to perform in relation to other countries, and it falls essentially, in my opinion, within the domain of external affairs.

If such a subject matter as this does not fall within external affairs then, if any power to deal with it at all by agreement with other States exists, that power must reside in the Australian States. It would surely be a surprising thing that, while power was given to the Commonwealth to deal with external affairs, the States alone could effectively enter into a convention for the control of material capable of being used for warlike purposes.

In considering this matter I have not examined the sphere of the executive as distinct from that of the legislative power as it does not appear to me that this question arises at the present stage.

I consider that, if the policy of the draft convention is approved, the Commonwealth should at the proper time signify its adhesion and sign the convention. It is very desirable that the extent of the power of external affairs should be ascertained and I can think of no better method of doing it than by passing legislation controlling, for example, private aircraft in the manner required by the convention and leaving the action of the Commonwealth to be challenged so that an authoritative decision may be obtained from the courts.

[Vol. 24, p. 113]

(1) Opinion No. 1444.