However, here's what we know:
* Otto's initial intentions: Otto likely hoped that Anne would return home and continue writing in her diary. He likely didn't consider the possibility of his family's permanent absence.
* Miep's actions: Miep Gies, the Frank family's helpful friend and helper, kept the diary safe after the family's arrest. She knew Anne's desire to become a writer and likely recognized the diary's significance.
* Otto's reaction after the war: Upon being released from the concentration camp, Otto asked Miep to return Anne's diary and other belongings to him. This suggests that he was aware of the diary's existence but didn't specifically instruct Miep to do anything with it.
Therefore, it is Miep's own initiative and understanding of Anne's wishes that led her to preserve the diary. She saw the diary as a precious record of Anne's life and a testament to her spirit, and she wanted to ensure its survival.
Otto later made the decision to publish the diary, fulfilling Anne's dream of becoming a writer and sharing her story with the world.