so there is precedent. how to take that issue away from MSM, should it happen?
In both the Marine and Cavalry examples, yes.
I believe, in both respects, the US was in a declared war.
Indian Appropriation War was passed in 1871. It stated that no Indian tribe would be recognized as an independent nation with which the federal government could make treaties.
Not certain about the Marine operation.
Also, IIRC, this is the only declared war prosecuted on US soil.
YMMV