This kind of treatment where, for example, a country X requires visas for citizens of country Y, then country Y will require a visa for citizens of country X, or the opposite, just to treat them in an equal way.
What's the term used to describe this kind of treatment when each party wants to treat the other the same way they are treated?
If both parties are doing the other a mutual favor, you could call it quid pro quo. It's originally a Latin term, but it's used often enough that you can find it in most English dictionaries. For example, Collins defines it as:
quid pro quo (n.)
1 a reciprocal exchange
2 something given in compensation, esp. an advantage or object given in exchange for another
However, if the one party is retaliating against the other for a perceived injustice, you might consider the term tit for tat, which CDO defines as:
tit for tat (n.)
actions done intentionally to punish other people because they have done something unpleasant to you
It can also be used as an adjective in hypenated form; for example:
The new law for stricter visa requirements is just the latest example in tit-for-tat politics between these two nations.
If you don't like tit-for-tat, there are several alternatives can be found in a thesaurus, such as reprisal or retribution.
Could you mean reciprocity, by any chance?
