WHAT DID CHURCHILL KNOW ABOUT PEARL HARBOUR BEFORE IT WAS ATTACKED?

We don't know.

The archives containing what Churchill knew about the Japanese fleet in that first week of December were sealed for 75 years. That 75 years is up this year, so we should be allowed to know what Churchill knew.

If you want to know what Churchill knew then make sure that the government archivists know that you want to know.