I read the following article:
from a seemingly reputable source (although it is a blog post).
The key claim:
Privately, Churchill suggested that America strike first, before it was too late. According to FBI records, he urged Sen. Styles Bridges, a conservative Republican from New Hampshire active in foreign affairs, to back a preemptory and devastating attack on Moscow. “He [Churchill] pointed out that if an atomic bomb could be dropped on the Kremlin wiping it out, it would be a very easy problem to handle the balance of Russia, which would be without direction,” Bridges told the FBI.
The provided source is the following document:
How reliable are those claims?