From 1942 to 1944, Dixon took leave from his judicial duties while he served as Australia's Minister (Ambassador) to the United States, at the request of Prime Minister John Curtin. On 27 May 1950, Dixon was invited by the United Nations to act as their official mediator between the governments of India and Pakistan over the disputed territory of Kashmir. His role was to continue conciliation talks between the two nations in the lead-up to a proposed plebiscite to be put to the residents of Kashmir. His role as mediator ended in October 1950, although he had left India in September frustrated with what he saw as an inability of the respective governments to negotiate.