The Second World War was New Zealand's greatest national effort to date. About 140,000 men and women were dispatched overseas to serve in fighting formations, 104,000 in 2NZEF, the rest in the British or New Zealand naval or air forces. In March 1944 there were just under 70,000 New Zealand personnel serving overseas. Fatal casualties during the conflict numbered 11,928 (Commonwealth War Graves Commission figures). Post-war calculations indicated that New Zealand's ratio of killed per million of population (at 6684) was the highest in the Commonwealth (with Britain at 5123 and Australia, 3232).
At home, New Zealand mobilised for war. At first the emphasis was on production for the war effort, New Zealand's primary produce supplying vital food stuffs for the United Kingdom. Conscription of men for the armed forces, from 1940, was matched by direction of labour for those not sent overseas. The development of a direct threat greatly intensified the process.
In July 1942 New Zealand's military mobilisation - the largest in its history - peaked with 154,549 men and women under arms (including those overseas) and a further 100,000 in the Home Guard. In all, 194,000 men - 67 per cent of those between ages eighteen and forty-five - and 10,000 women served in the armed forces. New Zealand devoted a very high proportion of its resources to the war effort: about 30 per cent of national income overall, with the figure rising to 50 per cent during the critical years 1942-44.
New Zealand's strategy in the Second World War was successful. Pre-war assumptions that seapower would be crucial to its physical and economic security proved justified, even if not in the way anticipated. It was American rather than British seapower that defeated Japan, and aircraft-carriers rather than battleships which were the decisive elements in the Pacific naval conflict.
Ultimately New Zealand depended on the overall Allied victory, and this was achieved in 1945 with the capitulation of Germany (on 8 May) and Japan (on 15 August), Italy having been defeated two years earlier. In this respect the war's outcome resembled that of its predecessor in 1918. While the British Empire/Commonwealth, with its allies, had prevailed in both, the second conflict had demonstrated even more forcefully the limitations of British power. Its default in the Pacific in 1941-42 was to have profound consequences for the future of the British Empire and in due course for Britain's status as a world power. This could not but fundamentally affect the position of New Zealand, though the implications were resisted at first by the New Zealand public. In the meantime the government sought to buttress British power in the Pacific by obtaining a security commitment from the United States, now clearly the dominant power in the Pacific, an objective which was achieved with the conclusion of the ANZUS alliance in 1951.
