Where does the power of the dual citizenship come from? If I have a passport each to two countries A and B, and am attempting to enter country C - is the benefit that I can present myself as a citizen of B and will be bound by some B-C covenants, regardless of whether I am a citizen of A, or is it from the fact that C doesn't know that I'm associated with A and only knows about my B loyalty because of the passport I…
Hiding the fact you're an A citizen is usually only helpful in hostage/terrorist situations which you'd probably want to avoid in any case.