"After all, Jack Benny knew that he had a choice when   
an armed robber threatened him with, "Your money or your life!""  
   
In a recent article in Word Politics (or Perspective in Politics, I can't remember at
all), Terry Moe (2005)discuss this kind of stuff in terms of agenda power. In fact, when
an armed robber threat someone, he actually set the terms of choice in a way that anyone
who prefers life to money will choose life. So, having the power to set the agenda is a
form of coerce someone to act as the agenda setter wants.
  
 Anyway, in political science there is a lot of discussion about the (three) faces of
power, namely: 1. physical coercion, threat of coercion and ideological power - to
influence the preferences of other.
   
 I don't have the references here, but if you search in Jstor for "faces of power" I think
you should find the original references.
   
Manoel Galdino