Fritz Haber, the German chemist who was awarded the Nobel Prize in 1918, was quite a contradiction. By helping develop industrial fertilisers, he could claim to have enabled millions avoid starvation. At the same time, he was the father of poison gas, unleashed for the first time by the Germans on the Western Front in April 1915, and it was at his institute in Berlin after WW1 that Zyklon B was developed, initially as an insecticide but then, by the Nazis, as the principal killing agent in the Holocaust death camps. Jewish by birth and yet patriotically German, Haber's war record did not stop him being ousted by the Nazis from all his eminent posts in the 1930s. He died in exile a broken man in 1934, largely shunned by the Western scientific establishment as a war criminal.
Haber once declared: "In peacetime, a scientist belongs to the world, in war he belongs to his country." As Robert Oppenheimer, the 'father of the atom bomb', was also to discover, war and ethics are uneasy bedfellows, nowhere more so than in the fields of science and technology. The historian Diana Preston explains how internationally agreed ethical red lines established before 1914 were rapidly smashed by the military imperatives of the First World War. Listen at unknownwarriorspod.co.uk. This is an Understanding History podcast.