Arndt was born to German parents in Istanbul, Turkey, in 1916. He had 12 years of classical schooling at Breslau, Silesia. In 1934 he moved to Oxford and studied Economics and Political science. After Oxford, Arndt moved to Warsaw, Poland for graduate study, where he learned Polish and, later, Russian. In 1939, after Hitler's invasion of Poland, he joined the anti-Nazi forces, was captured by the Germans and, after escaping from a German POW camp, spent a year in the Polish underground, eventually making his way back to Istanbul. From 1942 to 1945, Arndt was active in intelligence work on behalf of allied forces. He worked for the Office of Strategic Services, and the Office of War Information where he forged Nazi documents and passes until the end of the war. It was in Istanbul that he met and married Miriam Bach and had 2 sons (Robert and David) while teaching and studying at Robert College where he received a degree in mechanical engineering.
