It is lawful in this country (like most) to do all types of surveillance on foreign soil. The State Department has (or should have) some control to limit the excesses of the NSA, CIA or Military Intelligence surveillance of those we consider friends and allies -- most European countries governments fit that category.

Some foreign nationals who are hostile to US security interests may be resident in these "friendly countries'' and whether to request the assistance of those country's intelligence services or act extraterritoriality is a decision of the President as outlined in 50 USC § 1802 cited above.

FISA has become the NSA's "Monkey Court" rubber stamping court orders (warrants). What is worse is that the FISA Court acts ex-parte making secret decisions.