"…for a belligerent occupation to begin and relevant IHL rules to apply, the foreign troops’ presence within a State’s territory must not only amount to the exercise of so-called effective control, but also be hostile."

"…that belligerent occupation may also end by the conclusion of an agreement between the authorities of the occupied State and the occupier resulting in the transfer of sovereignty over the occupied territories."

SAUCE

https://www.europeanpapers.eu/en/system/files/pdf_version/EP_EF_2023_H_009_Federica_Favuzza_00689.pdf

As a direct result of the millions of persons illegally crossing our southern border, I suspect there's thousands of "foreign troops" inside our Republic throughout the 50 states… waiting for orders.