so in that sense, what klaus fuchs did, may have changed history. and have prevented, the use of another atomic weapon. >> yes, and that is true. you can also argue, that the means do they justify the end? that is that question. and there are factors of why we do not drop bombs, we have a bomb sitting on some island sitting there and mcarthur wanted to do that, and truman said no. and there were a number of factors, so you can't say it was just the fact that the that they were afraid of the russians, but that had to be a piece of it. along with other factors, so from a military point of view, that it had that consequence. from a political point of view, in the u.s., it certainly helped fire up, mccarthy in particular. and newspapers that were that way. so that had a profound effect on us. i think so. >> so you end the book with a question, about close, what klaus was he good or evil, was he a traitor or a hero. and the fact that you asked the question was kind of shocking. we think of me as a spy. and yet you can ask was he a trader or hero? and i g

she explains how she discovered klaus fuchs while researching her previous book. a screen