I think Aharon HaKohen’s lies for Sholom were “temporary”, meaning once peace was restored if and when the average person found out that the other party didn’t actually want to make peace and beg forgiveness first, he most likely wouldn’t mind but be happy peace was restored. That’s the classic example of lying for the sake of peace.
This is planned lying with the pretext of peace when in reality igniting war if it backfires once she finds out. So here’s where the common sense comes in… And most likely she will find out if it’s a long term thing. That’s without discussing the other risks involved in this scenario.