For most people on the Left the outbreak of the Spanish Civil War in 1936 was a defining movement. Here at last was a cause whose truth and justice could not be denied. Here was fascism in all its tawdry panoply, and only the Communist Party seemed willing to do anything about it. Small wonder that idealistic young men throughout the world volunteered to serve in the five International Brigades recruited to stiffen Republican resistance to Franco. The diary of Sidney Hamm, a young Welsh communist, written in a terse telegraphese - "Sick. Lounged about. Wrote home" - is a typical leftist document, made more poignant by Hamm's death at 20 in his very first hour of combat in the …