De Haan cultivated such rapport with British rulers that he threatened Zionist diplomacy.

Evidence

Apparently De Haan was capable of making a shambles of the attempt to effect good relations with the all-important mandatory power. The first British military governor of Jerusalem, Sir Ronald Storrs, was known for his distaste for the Zionists and the Arabs, yet De Haan seemed successful at gaining his favor. He made him the subject of a poem: General Storrs, you who hold in your strong hands Where our people trust in your esteemed leadership. — Ivan Davidson Kalmar, Derek Penslar, Orientalism and the Jews, 467