If the Americans have devised a scorched earth policy towards Taiwan in case of a mainland Chinese invasion, then they could keep it a secret. No reason to tell anyone else.To suggest or hint a scorched earth policy publicly, seems like not a subtle message to whoever is listening.
That is the other thing about this mainland China, Taiwan, United States triangle.
It is obvious to everyone, who is the pawn here, but that is not obvious to the pawn.
