You wouldn’t use Eminent Domain in such a case: that’s a strawman. Eminent Domain is not our last, best defense against the Chinese.
If the new owners of the land were committing a crime then you would prosecute in the usual way.
But if they came by their property legally and are doing nothing illegal, then seizing their property is criminal and immoral.
Ok. Bad example, but I still think using it to prevent the mosque from being built is feasable. It can be used for National Security reasons, and the terrorist money used for building the mosque is grounds enough.