What lost the war for the British in any case was the intervention of the French, who propped up the American Rebels without doing a single thing.

Oh that's so historically wrong. As a native of Virginia-- I can tell you there are plenty of roads and streets named for Count Rochambeau, who had 5 battalions of infantry in Rhode Island, and his contributions at Yorktown were a very big deal in the ultimate victory over the British there. Washington gave complete credit of the strategy used in Yorktown to Count Rochambeau, as well French Admiral DeGrasse, who effectively blocked relief efforts from British forces reaching Yorktown. Never mind the munitions and clothing and money the French provided.