The "blunder" of the title should be in the plural, for General Rikhye's measured assessment finds a combination of mistakes of judgment-by Nasser, by U Thant, by Israel, and by the big powers-responsible for bringing on the Six-Day War of June 1967. His book is also noteworthy for its factual, hour-by-hour account of his experience as the commander of the U.N. Emergency Force, first in dealing with the crisis precipitated by the Egyptian demand for its withdrawal, and then during the war itself when UNEF was caught between the warring armies.