The subjunctive mood is used in two types of constructions. The first is to express a condition that's hypothetical, doubtful, or contrary to fact:
If segregation were to remain lawful, then we would be ruled by a rigid adherence to the doctrine of precedent.
In your example, the country under discussion may be semantically hypothetical, but its description, i.e., the modifying clause beginning with where, is not, so the verb is the indicative was, not the subjunctive were.
The subjunctive appears in present or ongoing conditions in the present tense:
If music be the food of love, play on
(as opposed to past conditions:
If music were once the food of love, it is no more.)
But the present subjunctive is disappearing, and most people are comfortable with
If music is the food of love, let's go to a buffet.
The second construct involves verbs that ask, demand, regret, recommend, and prefer:
The Supreme Court ordered that legal segregation be abolished, although southern states preferred that it remain.
Note that the subjunctive is hidden in some formulaic imperatives:
Let it be.
Long live the Queen!