I don't find it so. You do need a strong background in a variety of topics: economics, history, science, history (of several varieties, military history among

I don't find it so. You do need a strong background in a variety of topics: economics, history, science, history (of several varieties, military history among them). You need some grasp of the importance of ideas and frameworks, and how human nature influences the way others think, speak and report. Amassing that is lot of work and a number of years. But it's worth doing in its own right. And from there, yeah, you needn't rely on others' summaries.