Wolfgang Schäuble's upcoming memoir details an internal CDU power struggle during the 2015 refugee crisis.

Edmund Stoiber attempted to overthrow Angela Merkel, an effort Schäuble did not support to avoid harming the party.

Schäuble criticizes Merkel's crisis management, suggesting she lacked proactive measures and transparency.

Despite disagreements, Schäuble maintained loyalty to Merkel throughout the crisis.

The memoir highlights Merkel's hesitance to negotiate with the Turkish president on refugee issues.

The book provides an insider perspective on CDU's internal dynamics and is scheduled for release next week.