I think many constitutional protections do apply in case the USA is prosecuting an individual, eg even as a non American you could take the 5th if an American court was trying to convict you.
However, when you're asking to enter the country as a non US citizen your options are essentially to do whatever the border services agents ask you to do or turn around and go home.
I think many constitutional protections do apply in case the USA is prosecuting an individual, eg even as a non American you could take the 5th if an American court was trying to convict you.
However, when you're asking to enter the country as a non US citizen your options are essentially to do whatever the border services agents ask you to do or turn around and go home.