Josten belonged to that group of young men and women, many from the Catholic nobility of Rhineland and Westphalia, who believed that the best hope for the restoration of the German monarchy lay with Hitler's vice-chancellor, Franz von Papen. Josten was employed in the Vice-Chancellery in Berlin and was present, with his friend Wilhelm von Ketteler, on the morning of 30 June 1934 when officers of the SS broke in and shot Papen's secretary, Edgar Jung, and the head of his press office, Wilhelm von Bose. Josten and Ketteler escaped, taking refuge in a barber's shop.
After the murder of Dollfuss in July, Papen reluctantly accepted the post of ambassador in Vienna, largely on the advice of Ketteler, who saw a chance of keeping Austria out of the Reich. At great danger, but helped as he later said by his youthful appearance, Josten acted as courier between Ketteler and the various conservative opposition circles in Berlin, south Germany and the Rhineland. He rapidly became disillusioned, as much by his distrust of Papen as the futility of establishing Vienna as a counterpoint to Berlin. In the course of 1935, he came under Gestapo suspicion and was offered an attache's position in Vienna at the ripe diplomatic age of 23, which he turned down at his family's request. The decision haunted him in later life, because he knew it spared him the fate of Wilhelm Ketteler who was murdered by the Gestapo on 13 March 1938, the day of the Anschluss. By this time, Josten was on the run, finding refuge first in Vichy France and, after its fall, in the eye of the National Socialist storm in Franconia.
For such a peaceable, scholarly man, resistance in the Third Reich was not only a matter of sabotage but of helping those under threat (including his large Jewish acquaintance) and nurturing circles of like-minded individuals that might preserve something from the wreck. His achievement was in the example he set to his large family and to his home city of Neuss, over which he later presided, in tiny rooms 10 floors above the Hamtorwall, wise, disillusioned and benign. For his British friends, he embodied the virtues of an extinct Germany.
But the conclusions he drew from his experiences in the Third Reich would be as unwelcome in modern Britain as in united Germany. He believed that the Germans were, by culture and tradition, vulnerable to dictatorship; and that the best defence of the peace and liberties of Europe lay with Britain's instinctive fairness, indifference and luck.