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.
During a “private conference with Churchill” while visiting Europe in the summer of 1947, Bridges claimed the former prime minister had “stated that the only salvation for the civilization of the world would be if the President of the United States would declare Russia to be imperiling world peace and attack Russia.”
If this wasn't done, according to the FBI report, Churchill predicted “Russia will attack the United States in the next two or three years when she gets the atomic bomb and civilization will be wiped out or set back many years.”
A full-fledged nuclear attack on the Kremlin didn't seem to faze Bridges, who’d been a sharp policy critic of Roosevelt and Truman.
Bridges mentioned this conversation with Churchill only while talking to a G-man about “other matters,” according to the agent who compiled the report. It noted that Bridges “concurs in Churchill’s views and that he sincerely hopes that our next President will do just that before Russia attacks the United States.”
Others close to Churchill heard similar bellicose sentiments. His personal physician, Lord Moran, recalled that Winston advocated a nuclear knockout blow against the Soviets during a conversation in 1946. “We ought not to wait until Russia is ready,” Churchill said. “America knows that fifty-two percent of Russia’s motor industry is in Moscow and could be wiped out by a single bomb. It might mean wiping out three million people, but they [the Soviets] would think nothing of that.”
Winston paused and smiled as he thought of this grotesquerie. “They think more of erasing an historical building like the Kremlin,” he added.
from: Thomas Maier,
When Lions Roar: The Churchills and the Kennedys 