The US views that US law applies worldwide. There is no requirement that you be anywhere near the US to be under US jurisdiction for an alleged offense against the US, according to the US.
Also, that constitutional protections are suspended within 100 miles of a land, sea, or air border.
4A still doesn't permit you to destroy the evidence. Resist on 4A grounds, destroy the evidence, 4A reasons get overturned - you've got yourself a conviction. US v. Akram Musleh.