"Britain has never been defended from an "Invasion" on British soil by American forces.
Dont mean to be technical,..."
Then leave that last word off such a sentence, because it is only technically true with it.
Hitler had no use for England and wanted the Lion dead. Because an American commander in chief was who happened to be no blow hard and also happened to be gung ho for a fight with Hitler got lend-lease going, England had the wherewithall, long befor American troops entered the fray, to stave off disaster.
Still, technically speaking that was not a defense from invasion on British soil