The Japanese title of this book may be translated into English as 'Between War and Peace'. The author, Professor Ping Yi (Peking University Law School), examines Japanese 'Just War' concepts between just before the Sino-Japanese War (1894) and the outbreak of World War I (1914). In classical Japanese international law textbooks, this period – following an earlier 'Just War' era – was characterized by a theory of 'indiscriminate war'. Although the idea of 'indiscriminate war' is neither self-evident nor clearly defined by Yi, she attempts to question the meaning of the theory that every war was to be treated equally and not distinguished by cause. Yi seeks an opportunity for the restriction or denial of war by categorizing erstwhile Japanese 'Just War' theories into three groups: (1) 'Extralegal Faction', (2) 'Adjudicating Faction', and (3) 'Implementing Faction'. To this end, Yi has plowed through tomes of old and mostly abstruse Japanese legal literature. She discovers that these theories were eventually used to justify the Russo-Japanese War, despite their potential function of restricting wars. Yi tries to uncover dangerous pitfalls, such as the intention to obtain quid pro quo, the game of politics, and the pro-war propaganda underlying the then Japanese 'Just War' theories. Yi's message is clear: we cannot stop thinking about the relationships between war/peace and law/politics. Readers may access the Japanese original for free online. An English summary of the monograph by the author is available in the publisher's FICHL Policy Brief Series (no. 12, 2013).