The National Federation of Women's Institute (NFWI) and other WI organisations in Scotland, France and Canada, began negotiations with the aim of establishing an international group for National Women's Institute bodies across the world relatively early in their existences. However, the fact that these bodies in other countries were often run by government agriculture departments made this impossible as the non-British, French or Canadian constitutions and structures were too dissimilar to make the plan practicable. The International Subcommittee therefore worked on a semi-official, ad-hoc basis from 1926, organising visits from other WI organisations across the world, while a resolution was passed in 1927 to further closer relations with similar associations. The Subcommittee was officially established as a standing committee in 1930 to deal in particular with the arrangements for the NFWI's representation at meetings of the women's section of the International Commission of Agriculture and with presenting recommendations of the international bodies to the Executive Committee. In 1932, it was involved in sending information on the annual meetings resolution on disarmament to the British Government, the League of Nations and other bodies; the NFWI had been a member of the Advisory Council to the League of Nations Union since 1919, members of the Executive Committee attending peace conferences in this capacity.
Mrs Alfred Watts was successful in asking the International Council of Women's to hold an international conference of rural women's organisations in 1929. A standing liaison committee was formed at this meeting which, in the mid-1930s resulted in the formation of the Associated Countrywomen of the World (ACWW). In 1935 it was decided that the NFWI should join the ACWW, an association that was still in existence in 2005. In the post Second World War period, it was active in organising trips to branches by other similar groups from across the world and visits from German women's groups in particular. Additionally, American residents and visitors were welcomed to headquarters on many occasions and the number of commonwealth students also increased as the subcommittee worked with the British Council to improve the welfare facilities available to them. In 1950, the NFWI joined the Institute of Rural Life at Home and Overseas to assist administrators going out to work in Commonwealth countries and in 1954 the words 'To promote international understanding amongst Countrywomen' were incorporated into the NFWI's constitution. The International Subcommittee took active part in international projects such as the World Refugee Year in 1959/1960. The major campaign of the 1960s was the Freedom From Hunger Campaign, aimed at improving conditions in various parts of Africa and included the building of a Farm Institute in Karamoja in Uganda as well as funding a Lady Aberdeen scholarship used to train women in nutrition and dietetics and a contribution to the development of a new University Farm in Trinidad. Between 1962 and 1966 the movement in Britain raised £182,000, while WI markets raised £3000 to build and equip a trade store in the Radisele area of Bechuanaland in order that local farmers could sell and store their crops, thereby radically improving the local economy.
By 2002, International Affairs were dealt with by the NFWI's Public Affairs Subcommittee that had responsibility for this as well as rural and home affairs. In 1997's Resolution in support of Agenda 21, the NFWI reiterated their long-standing commitment to sustainable development and the environment including in the international field as well as Third World debt cancellation and fair trade.