Comprehension of this competent biography in the ""World Leaders Past & Present"" series may be limited by young readers' unfamiliarity with communism and Czechoslovakia. Navazelskis ably re-creates vibrant moments in history; her book is thoroughly researched and capably organized. Its scope, however, is necessarily broad--reaching back to Dubcek's parents and encompassing the vital events of the past year in Eastern Europe. To readers unversed in the history, politics, geography, governmental structures, and traditions of this part of the world, the impact of Dubcek's role may remain obscure. For research, though, this volume offers dense thickets of information. Further reading; chronology; index.