Which word or phrase describes a situation where the answer is both a pro and a con?
You can argue such a situation (or policy) both ways.
There is more than one way of looking at it.
The outcome could go either way.
It might be a compromise decision or policy that could lead to unintended consequences.
The decision rests on a value judgment.
One term that is sometimes used is "mixed blessing."
The most obvious one to me would be...
double-edged sword
A situation or course of action having both positive and negative effects