He was right. His only failure I think was to see it as a serious threat. How could such a retrograde force be such a threat to the West?
And common people of Churchill's day wouldn't have stood by and allow atrocities we, the "enlightened" of today, allow to take place in our very mists, and on regular basis.
The people of his day would have been up in arms and dealt with the perpetrators themselves. Rabble-rouser I'm not - just stating fact.
"The only thing necessary for the triumph of evil is for good men to do nothing." - Edmund Burke (1729 - 1797)
In Churchill’s day, first the Nazis were the biggest threat, then communism. He was the first to call those what they were.
He knew Islam would be a threat to the west eventually, after communism was defeated.