For the political scientist in America there can scarcely be a more fascinating or more elusive study than the Soviet Union. The first enticement is the menacing importance of Soviet power. Then there is the miracle which in a single generation has changed a defeated and disintegrating agrarian society into one of the two greatest industrial and military States of our day. But these are claims to everybody's attention. The peculiar challenge to the professional student of social phenomena is another matter. For him Russia now is an enormous but dimly lighted laboratory in which doctrine is tested by experience, where the strain between ideology and reality is carried to a pitch never previously attempted, where techniques are developed by which a small elite secures a steady ninety-nine per cent of formal acquiescence from a population of two hundred millions, where political and economic strength is accumulated by processes in which what we consider normal human reactions are choked off by fear or concealed in the trite responses of an authorized litany.