When international tensions began to develop in the 1930s, Clarice initially held to her pacifist principles. She appeared at peace assemblies and in 1935 was one of the key speakers at a women's peace conference in the Keir Hardie Institute. As the fascist threat grew more acute, however, she modified her views. Although she abhorred the many side effects of the Second World War, such as the lowering of educational standards, by 1945 she was demanding total victory and the crushing of German power. Clarice Shaw's activities during the war represented the height of her many achievements. She was chairman of the Scottish Labour Party, a Labour Councillor, and a member of the Scottish Committee of Co-operative, Labour and Trade Union Women, founded—partly by her—in 1934. She had close links with the Scottish Trades Union Congress and the Women's Co-operative Guild in England. When her husband died in October 1942, she committed even more time and energy to the Labour Party.