The Japanese word kuzushi literally means ‘undermining’ and in the context of martial arts it means destabilising and subsequently unbalancing an attacker as a precursor to the execution of a technique, whether a throw or an immobilisation. The term kuzushi is well-known in Judo circles but, although Aikido techniques also incorporate the use of kuzushi states, in the author’s experience they are rarely identified explicitly by Aikido masters, even though observation reveals very clearly that they are utilising kuzushi states effectively. Awareness of kuzushi adds a new dimension to Aikido practice, giving it a rational basis for the effective execution of all techniques, and without relying at all on uke being passively compliant. This book identifies major kuzushi states and shows their implementation for a range of Aikido techniques.