Early in the 20th century, New Zealand was involved in world affairs, fighting in the First and Second World Wars and suffering through the Great Depression. The depression led to the election of the first Labour Government and the establishment of a comprehensive welfare state and a protectionist economy. New Zealand experienced increasing prosperity following the Second World War, and Māori began to leave their traditional rural life and move to the cities in search of work. A Māori protest movement developed, which criticised Eurocentrism and worked for greater recognition of Māori culture and of the Treaty of Waitangi. In 1975, a Waitangi Tribunal was set up to investigate alleged breaches of the Treaty, and it was enabled to investigate historic grievances in 1985. The government has negotiated settlements of these grievances with many iwi, although Māori claims to the foreshore and seabed proved controversial in the 2000s.