THE responsibility for directing New Zealand's war effort lay with the Cabinet—or rather, after July 1940, with the War Cabinet—whose decisions were transmitted through the Minister of Defence to the services. In arriving at these decisions on broad policy, the War Cabinet was assisted by committees dealing with specific aspects of the multifarious problems involved in waging war.

In 1933 a New Zealand Committee of Imperial Defence had been set up to co-ordinate all preparations for national defence, both military and civil. It consisted of a number of committees of Cabinet Ministers and representatives of all Government departments which would be concerned with the security and supply of the country in time of war. All its decisions were advisory and were sent to Cabinet for action if the British Committee of Imperial Defence approved them.

In 1936 the name of the committee was changed and it became known as the Organisation for National Security. At that time it consisted of twelve functioning committees, of which the most important were the Chiefs of Staff Committee, which advised on all service matters, and the committee dealing with co-ordination and the preparation of the Government War Book. Others dealt with supply, mapping, manpower, emergency precautions and the like.

In May 1937 a Council of Defence was formed to direct the activities of the various ONS committees. It consisted of the Prime Minister and the Ministers of Defence and Finance. The three Chiefs of Staff, the Secretary to the Treasury, and the Permanent Head of the Prime Minister's Department attended all meetings in a consultative capacity. Other members attended from time to time by invitation of the Prime Minister. Major Stevens¹ was seconded from Army to the Prime Minister's Department and appointed secretary both of the Defence Council and of the ONS.

After the war started the original function of the ONS, that of preparation, was at an end; but the committees continued to act as consultative and deliberative bodies and the organisation, within the Prime Minister's Department, was responsible for co-ordination of the country's total war effort. The secretary (Major Stevens was succeeded in 1940 by Mr Foss Shanahan¹) also acted as secretary to the Chiefs of Staff Committee, which naturally became the most active section of the ONS. In addition the ONS provided the secretariat for the War Council, a further advisory body which functioned from January 1940 until September 1942.