The Bureau - inconsistency..

Much as I admire 'The Bureau'  it doesn't seem entirely consistent.

The boss visits his female spy to question her about having ever seen any Americans in Tehran when she was there. 

This because the  Irani they want to 'turn' is working for the CIA they now believe.

She says there are no Americans in Tehran.  Relationships so bad between the two countries I guess.

But why would top level spy agencies necessarily use their own countrymen for all their machinations?

That's ludicrous isn't it?  Unworkable.