I believe the answer is The Fireside Chats.
Answer:
If their writing dissapears, then, what is known about that civilization is also likely to dissapear, unless their previous writing was preserved in some other way.
This is something that has actually happened often in history. For example, the library of Alexandria, in Egypt, was the largest library of the Ancient World, and it was burned down by Caliph Omar in 642 AD. Countless works by Ancient authors, that gave account of civilizations, cultures, philosphies, and religions, were lost, and there is no plausible way to recover such knowledge in the current era.
Explanation:
Roosevelt felt that despite Russia being communist, Hitler posed a more immediate threat, and that before they get at each other, Hitler had to be knocked down. Churchill believed that Hitler would do anything to get what he wants, albeit killing millions or sell his soul to the devil himself. Hitlee also openly voiced his idea of fascism everywhere, which didnt exactly comfort churchill