Prof. Ishihara's work defined the field of Earthquake Geotechnical Engineering over the last few decades. His book captures the evolution of the field in a concise manner. It captures his philosophy and most of the concepts he put in the book in the mid-1990s are still state of the art today. Prof. Ishihara is a past president of ISSMGE and he recently passed (Dec 2025). He co-created TC203 (which was formerly TC4). This book best represents the field of Earthquake Geotechnical Engineering at the present time.