There doesn't even need to be a second additional secret letter. Just a bit of emphasis and a wink in the exact way Congress responded to Washington. "This Cong

There doesn't even need to be a second additional secret letter. Just a bit of emphasis and a wink in the exact way Congress responded to Washington. "This Congress does not wish to see your army burning down New York." They never explicitly forbade some unrelated good patriots from taking up that cause out of sheer love of country (or, perhaps even, love of money).