They will investigate your background, whether you have any ties to family abroad by which you could be blackmailed etc.
An acquaintance of mine (from East-Germany) had a US boyfriend who started to work for Lockheed - in the interview he was asked "Why doesn't your Eat-German girlfriend answer her phone?". She said she got some calls from an unknown number and didn't pick up.
Edit: I meant Eastern Germany, after unification (but her parents lived in East-Germany, i.e. the GDR) my bad.
How did she know the call was from an unknown number as a normal person in East Germany in the 80s or earlier? (Ie when it was still called East Germany)
I should have written Eastern Germany, it was long after unification and there were smart phones involved (but in the US security apparatus, Eastern Germany may still be suspect).
An acquaintance of mine (from East-Germany) had a US boyfriend who started to work for Lockheed - in the interview he was asked "Why doesn't your Eat-German girlfriend answer her phone?". She said she got some calls from an unknown number and didn't pick up.
Edit: I meant Eastern Germany, after unification (but her parents lived in East-Germany, i.e. the GDR) my bad.