Not true in any respect, Schweik, I am afraid to say.

Serbia nor Croatia are members of the EU. As for Cyprus, there is no "war". The island is partitioned between the Cypriot Republic, which is a member of EU, and a statelet in North Cyprus which is not, and which is not recognised by anyone, except Turkey, which is of course not in the EU.

The very fact that Turkey recognises North Cyprus is a guarantee that, so long as that is the case, it will not be given EU membership, even if all the other conditions it would have to satisfy were met - which is a very long way from happening.