That is the only problem I see. Are you counting Domestic invasion as some of the foreign? Domestic invasion (ner do wells) will be a problem as well.
No free stuff means no freeloaders.
I came to work one morning to find an infestation of ants. So I cleaned the place, got them to actually vacuum the carpet and change the trash bag in the can instead of just pulling stuff out of it.
The next day there were no ants. They went looking somewhere else for a free lunch.
End welfare and the ne'er-do-wells will toddle off to find it in the nearest blue state.