By the late 19th century many New Zealanders were coming to regard themselves as a new nation. Most of those of European background had been born in New Zealand and had no memories of or nostalgia for Britain, often called “home.” In the 1890s New Zealand Natives Associations were established by native-born European New Zealanders. Success in sports, especially rugby, spurred national pride. An even greater influence was war. New Zealanders served on the British side during the South African War (1899–1902), during which time they earned a reputation as being superior to the British at fighting a guerrilla war. World War I greatly stimulated national sentiment. During the warfare at Gallipoli, Turkey, and later in France, New Zealanders proved to be excellent soldiers. But while the war boosted nationalist sentiment among both troops and civilians, the price was terrible: nearly one of every three men between the ages of 20 and 40 was killed or wounded. The loss in leadership in the following years was considerable.

At home the war brought prosperity, as export markets were assured and prices good. Domestic unity was only slightly shaken by the antiwar feeling of a faction on the political left. Massey remained prime minister, but, in the wartime coalition government (1915–19), Ward and the Liberals carried great weight. The Reform Party stayed in office until 1928, led after Massey’s death in 1925 by Joseph Gordon Coates. The party survived the first postwar economic depression but not that of the mid-1920s. Led by Ward, the Liberals, under the new name of the United Party, were victorious in 1928; they thus had to face the deepening depression of 1929–30. After Ward’s death (1930) and at the height of the depression, Reform and United formed a new coalition (1931) under the premiership of George Forbes, which lasted until the election of 1935 brought in a Labour government.

Some postwar developments were of great importance. In external affairs Massey led a delegation to the Paris Peace Conference and signed the Treaty of Versailles and so committed New Zealand to membership in the League of Nations. New Zealand thus began to acquire the status of a sovereign state, though Massey denied this consequence. The Liberals, especially Seddon, had already taken steps toward autonomy within the empire. At the series of colonial and imperial conferences from 1887 onward, New Zealand had followed Canada and Australia in asserting its right to a voice in certain foreign policy issues. Seddon argued vehemently against British reluctance to acquire more Pacific islands while permitting German influence to grow in Samoa.

New Zealand legislation to restrict Asian immigration was sharply and obstinately at variance with British policy. Western Samoa (now Samoa), which New Zealand had captured from the Germans in 1914 and over which it was granted a mandate in 1920, also provided occasions for British and New Zealand differences.

Reform leaders professed little love for the principle of Commonwealth autonomy. New Zealand took a passive part in the conferences leading to the Statute of Westminster in 1931 and did not adopt it until 1947. But the substance of autonomy had been enjoyed before.

The major domestic achievement of the Reform administration was a system of export-marketing agencies in which authority was shared by producer and state. That system laid the foundations of a collectivist marketing structure. J.G. Coates was the most energetic minister in Forbes’s coalition government. His attempts to counter depression concentrated on the farmer in order to revive the country. To increase export receipts, he devalued the New Zealand pound. He also protected farmers against foreclosure and set up a credit agency.

When overseas prices began to recover in 1934, the country was financially strong, but little had been done for the unemployed. Conditions in towns and relief camps led to rioting, violence, and widespread discontent, all of which were favourable to the Labour Party. The Labour Party had been formed by socialist and radical groups in 1916. During the 1920s it was predominant only in working-class electorates. In its quest for votes, however, Labour increasingly abandoned its socialist theories and adopted welfare and credit-reform proposals, which had wider appeal. In the election of 1935 Labour won a considerable victory; successful in the towns, the party also won in many rural areas. Prices for dairy exports were slowest to recover, and many dairy farmers were drawn by Labour promises of a guaranteed price. The victory was particularly notable in terms of seats, for a right-wing third party (the Democrat Party) split the conservative vote to Labour’s advantage. The National Party, successor to the coalition, was rendered temporarily ineffective.

The new ministers, among whom the most notable were Peter Fraser and Walter Nash, showed great energy. Led by Michael Joseph Savage, they had the good fortune to govern a country to which prosperity was returning. The farmer enjoyed increased earnings; the worker, increased wages and shorter hours. Jobs were multiplied by a public works and housing program. The education system was revitalized. In 1938 the Social Security Act provided a state medical service, extended the pension system, and increased benefits. The expansion of secondary industry was accelerated after the outbreak of World War II in 1939.

World War II and the postwar decades

The alacrity with which New Zealand went to war in 1939 showed that dominion autonomy had not weakened the country’s ties with Great Britain. At first the war resembled that of 1914; troops were sent to Egypt to train for the European conflict. There they were directly involved by the enemy advance there and saw action in Greece, Crete, North Africa, and Italy. After 1941 New Zealand was directly threatened by Japan, which meant New Zealand had to concentrate forces in the Pacific. Well before the end of the war, the strain upon the country’s manpower, together with the demands of home production, forced a reduction of commitments in the Pacific.

The Pacific theatre was dominated by the United States, the forces of which provided New Zealand’s sole defense. The fact that disaster was averted by American, not British, forces required a change in New Zealand’s attitudes; security was conferred by a foreign, though friendly, power. External relations in the postwar period reflected that new situation, chiefly through the ANZUS pact (1951), a defensive alliance between Australia, New Zealand, and the United States.

At home the entire economy was mobilized in the war effort and subject to controls. Conscription and direction (directed allocation of the labour force to strategic industries) sent manpower into the military forces and essential occupations. Heavy taxation, war loans, bulk purchase, and controlled marketing kept the economy in a firm grip. They also kept inflation in check; with price control and wage restraint, they amounted to a complete policy of economic stabilization, applied by a Labour government that remained in power until 1949. Savage died early in the war. Fraser, his successor, and Nash were chiefly responsible for the tasks of administration during the war and of reconstruction after peace returned.

Sidney Holland led the revival of the National Party, which culminated in victory in 1949. Discontent with controls and with the rising cost of living helped to swing support away from Labour. The National government benefited from its vigorous handling of a serious waterfront dispute in 1951, but in later elections its majority narrowed until Labour returned in 1957. In 1960 the National Party, led by Keith (later Sir Keith) Jacka Holyoake, was returned to power, which it retained until 1972. In that year Labour won a huge victory under Norman Eric Kirk. His death in office in 1974 was the prelude to as great a National victory in 1975, under a new leader, Robert Muldoon.

After World War II, New Zealand began to play a relatively independent role in world affairs. That development, in fact, had begun before the war, when the Labour government’s attitude to the League of Nations was coloured by an idealism that clashed with British policy. During the war, Fraser had insisted on an independent voice in the councils of the Allied Powers. At the formation of the United Nations in 1945, he became a notable spokesman for the small powers and made a large impression on the Trusteeship Council. None of those developments weakened New Zealand’s close affinity with Great Britain, its loyalty to the Commonwealth, or its dependence upon the United States.

Geography and insecurity shaped postwar foreign policy. With Australia, New Zealand claimed a voice in settlement in the South Pacific Commission (now the Secretariat of the Pacific Community) and in the transfer of authority in Western Samoa, successfully completed in 1962. New Zealand became deeply involved in Southeast Asia. From 1951 it provided assistance through the Colombo Plan. New Zealanders fought in Malaya (now part of Malaysia), Korea, and Vietnam. Further, New Zealand became a member of the Southeast Asia Treaty Organization in 1954 and supported the United States by sending troops to Vietnam. That reflected fear at the growth of communist power in Asia. The independent spirit of the postwar years was modified to a greater dependence on Western powers during the 1950s and ’60s. In the later 1960s, involvement in the Vietnam War led to a vigorous and continuing public debate on foreign affairs. After Vietnam, debate turned largely on the problem of South African apartheid, especially in the context of sports relations with South Africa and with African countries at Commonwealth and Olympic games.

The 1970s and ’80s were difficult economically for New Zealand. The combination in the early 1970s of high energy prices and Great Britain’s entry into the European Economic Community (later succeeded by the European Union) brought about a severe economic recession. Inflation and unemployment skyrocketed, and thousands emigrated to Australia. The response of Muldoon’s National government was interventionism on an unparalleled scale: the government borrowed funds from overseas and ran up huge budgetary deficits, in part to finance large industrial developments; in the early 1980s it placed a freeze on wages and prices; and it attempted to regulate interest rates. Dissatisfaction with that program led in 1984 to the election of a Labour government, headed by David Lange.

A major change during that period was the growing participation of women in the workforce and their assertion of rights in the public arena. In the 1970s and ’80s the women’s movement was well organized, and an increasing number of women entered the mainstream political arena or engaged in feminist politics. By the 1990s women had attained the highest governmental offices.