During the First World War, Alexander served as a Sergeant Major in the Princess Patricia's Canadian Light Infantry, as he was unable to join the British forces as his height was only 5'1".
He was made a Member of the Order of the British Empire in 1918 (investiture 15 November 1919), and in 1919 married Doris Emily Kibble, whom he had met in the offices of Lord Beaverbrook.
He was instrumental in founding the Society for Individual Freedom and Oliver Smedley described himself and Alexander as "the only active free-traders left in England in the 1950s".
He believed that the abandonment of free trade in 1917 began "the lowering of the standard of life by stopping goods reaching people" and that it was responsible for "the closed market behind which monopolies and price rings of labour and capital have grown up".
[2] He argued for the restoration of free trade "regardless of what other nations may do" and asked: "...does the housewife improve her position by buying the poorest quality goods at the highest price or not?
[6] "Protectionism", Alexander wrote, "is akin to socialism and no free enterprise political party in an island nation dependent for its life on international trading should ever have had anything to do with it...capital and labour need a return to the natural disciplines...[these] can only be restored as a result of a balanced national budget, a limitation on the volume of circulating paper money of all kinds, and the abandonment of import restrictions and duties so that all home production in cost and quality is constantly challenged by the alternative of the product from overseas".