What is the smallest island nation in the world?

Nauru

Explanation:

The smallest island nation in the world is Nauru. Nauru is also the third smallest nation in the world, with only Vatican and Monaco being smaller than it. This nation is located in Oceania, being composed on only one island, and its total territory is only 21 square kilometers. The island has a nice and pleasant tropical climate throughout all of the year, as well as nice and attractive beaches, but the tourism is not developed at all, and it actually the least visited nation in the world. The main reason why the island is not visited is because it is very far away from the other nations, especially the larger ones, and it is very expensive to visit it. Unfortunately, Nauru faces a big danger with the rise of the sea levels, as all of the island has very low elevation, so if the sea level rises slightly more, the island will be almost entirely under water.

separation of church and state? not sure what you mean.