In the short story The Kidnapped Prime Minister, David MacAdam is the prime minister of Britain in question. The text of the story suggests that his tenure is during a time during the First World War, and probably after the events of The Mysterious Affair at Styles. Just before Mr MacAdam was kidnapped he had been scheduled to attend an Allied Conference at Versailles. He was expected to speak out strongly against "pacifist propaganda" being circulated by German agents which were all calling for a negotiated peace. Hastings records that MacAdam is considered "Fighting Mac" by his party. He had strenuously and unequivocally combated the Pacifist influence which was becoming prevalent. Hasting notes that MacAdam was "more than England’s Prime Minister – he was England; and to have removed him from his sphere of influence would have been a crushing blow...."
How Poirot resolves the crisis forms the main plot of the story.