Hitler is moving west, France has fallen, and Great Britain is in danger of crumbling like a stale crumpet. And that's just the beginning, folks.

FDR wanted to get people thinking in terms of worst-case scenarios, but he knew that you can't just say to someone, "Imagine the worst thing that could happen." (Because they'd probably say, "Um, no thanks," and go off to drown their anxieties in a Netflix binge.)

Instead, FDR does the imagining for everyone himself and then shares those dreadful thoughts with anyone who'll listen (or has to listen, like the members of Congress). Obviously, his speculations are frightening—they're all about the fall of the USA.

Yeesh.

For some, this thought was absurd or just plain unimaginable, so FDR recalls the fear in the air during World War I, when American allies were fighting to maintain democratic sovereignty. He offers a reminder of worst cases of the past, when:

[…] the American people began to visualize what the downfall of democratic nations might mean to our own democracy. (18)

In doing so, he indicates such a time has come again, and the sequel is even worse. (Isn't it always?)

Fear permeates the whole of the "Four Freedoms" speech in much the same way it permeated American culture in 1941. And FDR speaks to this feeling of anxiety and foreboding when he says:

Every realist knows that the democratic way of life is at this moment being directly assailed in every part of the world—assailed either by arms, or by secret spreading of poisonous propaganda by those who seek to destroy unity and promote discord in nations that are still at peace. (23)

In other words, it's time to face facts. Responding with fear is appropriate because war, whenever and wherever it is waged, is frightening. And any war, whether civil or international, is always too close. This is why FDR states:

[...] the future of all the American republics is today in serious danger. (45)

"The fascists over in Europe aren't messing around," FDR is saying. "And that's why I can't mess around with hopeful talk. Things are bad."