This is the third volume of a monumental study of ""the principles of democratic socialism"". The first two books were Contemporary Capitalism and The End of Empire. As the author clearly states in his opening words, ""Any such study which ignored the menace of nuclear war would be incomplete, to say the least of it"". Given this context, John Strachey has here presented us with what is surely one of the finest, broadest, most careful, and best thought-out considerations of ""the dilemma upon the horns of which the progress of physical science has impaled us"" to appear thus far. The very least of the points he makes are worthy of far more space than can be given them here, but a glance at the overall plan of the book may give some idea of the basic approaches: it is divided into four parts, entitled ""The Stability of the Balance"" (analyses of all present aspects of the arms race): ""Disarmament"" (obstacles to, and ways and means of, achieving it); ""Intentions"" (of Russian and the West); and ""Possibilities of Survival"" (a meticulous weighting of all proposed and possible solutions). After all of this, when the author outlines his own proposals they cannot be dismissed out of hand. ""What we have a right to demand of the men of power"", he says,""is that they shall cease to regard...the progressive development of a world authority as an academic, dreamy speculation, and see that it is indispensable to human survival in the nuclear age."" The closing chapters are devoted to the all-important questions of how, and whether, we can set about trying to obtain such a ""world authority"".