In my original example the dilemma was between denying a suspected terrorist the right to consult with a lawyer and risking a nuclear terrorist attack. I gave this as an example of when idealism and pragmatism are in conflict. When you objected that this was unrealistic, I responded by giving a real life example where idealism and pragmatism were in conflict.

The purpose of my example was to create a situation where it should be obvious the right move is to go against idealism. The reason is, if your starting point is something like "We must never deny people their rights" I'd like to show you an extreme example where, actually, we must. If you can agree on the extreme example, then the discussion becomes a matter of degree - i.e. when is it okay to deny people their rights versus when it is not. This is actually the more nuanced and realistic discussion that has applicability to the real world.